Latest Devonian (Strunian) Ostracoda from the Buttons Formation, Bonaparte Basin, northwestern Australia: biostratigraphy, palaeoecology and palaeozoogeography PETER J. JONES JONES, P.J., 2010:10:29. Latest Devonian (Strunian) Ostracoda from the Buttons Formation, Bonaparte Basin, northwestern Australia: biostratigraphy, palaeoecology and palaeozoogeography. Memoirs of the Association of Australasian Palaeontologists 39, 261-322. ISSN 0810-8889. Twenty-seven ostracod species are reviewed and referred to 22 benthic genera: Armenites, Bairdia (Bairdia), Bairdia (Rectobairdia), Baschkirina, Beyrichiopsis, Cavellina, Chamishaella, Coeloenellina, Cryptocyprois, Diphyochilina, Geisina, Indivisia, Katatona, Knoxites, Marginia, Notoscapha, Parabolbinella, Parabouchekius, Rhytiobeyrichia, Serenida, Shishaella, Sulcella and Urftella?. The fauna also includes the eridostracan Cryptophyllus. Species newly described are Beyrichiopsis? anogma, Beyrichiopsis teicherti and Serenida? alta; species newly recorded are Bairdia (Rectobairdia) aff. philippovae Egorov, 1953, Cryptocyprois sp. cf. C. subgibberosa Buschmina, 1977, Indivisia baschkirica Rozhdestvenskaya & Tschigova, 1972, Parabolbinella sp. A and Parabolbinella sp. B. Three biozones [Sulcella (Postsulcella) altifrons Zone, Diphyochilina tryphera Zone and Bairdia (Bairdia) ordensis Zone] are established and used for local correlation. Palaeoecologically, the ostracods are interpreted as indigenous, low energy thanatocoenoses, representing an Eifelian mega-assemblage, and are indicative of a shallow, generally well oxygenated lagoonal environment, below storm wave base. A gradual salinity increase is indicated by the appearance of stenohaline marine bairdioids in the upper part of the Buttons Formation. Long range correlation of this cosmopolitan ostracod fauna is with the late Famennian (Strunian, in particular). Strong zoogeographic links exist with the western margins of Palaeotethys (North Africa, Spain, France, Belgium, Poland), the East European Platform and Kazakhstan. Weaker links are with South China, northeast Russia (Omolon Massif) and the Cordilleran Province of North America. Benthic ostracods, lacking a pelagic larval stage, could not have crossed deep oceanic barriers. The observed zoogeographic links probably indicate that the shallow shelves of the western part of Gondwana and Laurentia-Baltica were close enough to permit genetic exchange and migration during transgressive pulses, along juxtaposed shallow shelves of the adjacent blocks of Gondwana and Laurentia-Baltica. A similar connection probably existed between the South China Plate and northwestern Australia, via terranes within the eastern end of the palaeotethyan equatorial belt. P. J. Jones (
[email protected]), Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia. Received 26 July 2010. Keywords: Ostracoda, Late Devonian (Strunian), Australia, biostratigraphy, palaeoecology, palaeozoogeography
DEVONIAN OSTRACODS were first reported from Western Australia by Teichert (in Matheson & Teichert 1948). From his preliminary examination of the fossil fauna, Teichert recognised the presence of Upper Devonian rocks in the “Burt Range Basin”, an area now referred to as the Burt Range Shelf at the southern end of the Bonaparte Basin (Mory & Beere 1988). The Late Devonian ostracods of the Bonaparte Basin were first described some 20 years later, at a time when few contemporaneous ostracod faunules had
been studied from other parts of the world (Jones 1968, p.12). Since that time, the global Devonian ostracod taxonomic database has increased considerably, as exemplified by the reviews of Gooday & Becker (1979), Groos-Uffenorde et al. (2000) and Gooday (2009). This has led to a greater use of ostracods for biostratigraphic purposes in the Devonian, particularly in Europe, North America, the former Soviet Union, and the People’s Republic of China. Late Devonian Ostracoda, in particular, have been much studied
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in Europe, the former Soviet Union, western Canada, and the People’s Republic of China (see the numerous papers cited by Gooday 2009 in his synthesis of Devonian ostracod research). Thus, it is desirable to review the first account of the Late Devonian Ostracoda of the Bonaparte Basin (Jones 1968) in the light of the later literature, and to compare the fauna with the various zonal schemes that have been proposed for benthic ostracods [as opposed to those based on Entomozoacea (‘fingerprint ostracods’) of which at least some species are pelagic]. The original monograph (Jones 1968) was later augmented by taxonomic studies on the beyrichioids (Jones 1985, 1987) and paraparchitoids (Jones 2004), but the result of subsequent collecting demonstrated that the
account of the benthic ostracod fauna of the Buttons Formation was far from complete. To present a more comprehensive account, the purpose of this study is to revise the taxonomy and biostratigraphical distribution of the benthic ostracod fauna of the Buttons Formation, to enhance its biozonal value for local correlation of the latest Devonian (Strunian) in northwestern Australia, and to evaluate its palaeoecologic and palaeozoogeographic significance. STRATIGRAPHY AND FAUNAS The Devonian and Carboniferous stratigraphy of the onshore Bonaparte Basin has been described in detail by Veevers & Roberts (1968), and a concise summary of Bureau of Mineral Resources (BMR) studies of the area over the years 1963-
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1971 has been provided by Roberts & Veevers (1973). Further aspects of the Devonian and Carboniferous stratigraphy have been described by Mory & Beere (1988) in their work on the
geology of the onshore Bonaparte Basin, and by Gorter et al. (2003, 2005) in a summary of the results of subsurface studies. In the southern part of the basin (Fig. 1), a horst-like block, the
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Precambrian Pincombe Inlier, separates the Burt Range Shelf in the southeast from the Carlton Shelf in the northwest. This division is used here in the following summarised description of the stratigraphy and faunas of the latest Devonian (Strunian) Buttons Formation. The summary is based on several sources (Gorter et al. 2003; Jones 1985, 1989; Mory & Beere 1988; Veevers & Roberts 1968), to which the reader should refer for further details. The outcrops of the uppermost Famennian (Strunian) and Tournaisian carbonate platform sequence are most complete on the Burt Range Shelf, where they attain a total thickness of about 1,150 m. Lagoonal carbonate rocks and sandstone (Buttons Formation), in part equivalent to outcropping carbonate rocks of a Famennian reef complex (Ningbing Group) on the Carlton Shelf, were deposited behind the reef-complex near the land to the south and east of the Precambrian Pincombe Inlier. The Buttons Formation is part of a carbonate platform succession that flanks the Precambrian Pincombe Range Inlier, and consists of over 350 m of sandy and silty limestone with minor silty dolomite and sandstone with thin beds of sandy limestone. The type section (section 105 of Veevers & Roberts 1968, p. 62, figs 30, 35) is along the east bank of the Ord River, just north of Buttons Crossing (Fig. 2), but neither the base nor the top of the formation are exposed here. Other sections (sections 145, 146 of Veevers & Roberts 1968, p. 62, figs 30, 39) have been studied in the Eight Mile Creek area (Fig. 3) where the Buttons Formation is disconformably overlain by the Lower Carboniferous (Tn1b) Burt Range Formation (Jones 1968, 1989). The Buttons Formation is richly fossiliferous and contains abundant ostracods (Jones 1968, 1985, 1987, 2004), calcareous algae (Veevers 1970; Mamet & Roux 1983), calcareous foraminiferids (Mamet, pers. comm.), conodonts (Druce 1969), brachiopods (Roberts 1971), corals (Hill 1954), bivalves, gastropods, stromatoporoids, crinoids, megaplants and miospores (Playford 1982). The original tentative age determination for the formation was based on the presence of the conodont identified by Druce (1969) as Polylophodonta sp. A, which ranges from 120 m to 250 m in the type section. This conodont element was thought to indicate an early Famennian (doIIβ-doIII) age (Druce 1969; Roberts et al. 1967, 1972), which was accepted as the age of the associated ostracods (Jones 1968). Thus, a substantial hiatus, involving much of the late Famennian, was thought to exist between the Buttons Formation and the overlying Burt Range Formation. Playford (1982) later
AAP Memoir 39 (2010) described miospores of the Retispora lepidophyta Assemblage from the type section of the Buttons Formation which indicated a latest Devonian (Strunian) age. Later studies of elements of the benthic ostracod fauna of the Buttons Formation (Jones 1985, 1987, 2004) are consistent with a Strunian age, and further support for this age is provided by a reassessment of ostracods in this paper. In the Eight Mile Creek area the base of Burt Range Formation is, on conodont evidence (Jones 1989), either at or very close to the Devonian-Carboniferous boundary (i.e., the Strunian-Hastarian boundary; within Tn1bα). The lithological contact between the Buttons Formation and the Burt Range Formation appeared gradational to Mory & Beere (1988), and because these authors dismissed the possibility of a hiatus between the respective Strunian and Tournaisian faunas, they regarded the units as conformable. An increase in the amount of carbonate in the Burt Range Formation, compared with that in the top of the Buttons Formation (Veevers & Roberts 1968, figs 30, 41), suggests a marine transgression took place early in the Tournaisian (Roberts 1985). However, there is a marked faunal break between the two formations, as shown by the ostracod faunas (Jones 1968, 1985, 1989), which probably represents the Hangenberg Event. This major extinction event was caused by a global fall in sea-level that occurred just prior to the Upper praesulcata Zone, the uppermost conodont zone of the Devonian (Ziegler & Sandberg 1984). Druce (1969, 1974) suggested the basal beds of the Burt Range Formation may be of latest Devonian age, but could not recognise the praesulcata Zone in terms of local conodont biostratigraphy. It is also significant that the Hangenberg Event has been recognised as the Yellow Drum regression in the Canning Basin (Talent et al. 1993), where it is identified from the negative shift of carbon and oxygen isotope values in the Yellow Drum Formation, 4 m below the Devonian-Carboniferous boundary, marked by the first appearance of the conodont Siphonodella sulcata (Andrew et al. 1994). Thus, it is concluded that the contact between the Burt Range Formation and the Buttons Formation is a disconformity, which in the present state of knowledge, can be taken as a close approximation of the Devonian-Carboniferous boundary. Material and methods The sample base is largely the material collected during the BMR studies of the area in the 1960s (Veevers & Roberts 1968), and later augmented by the collections made by R.S. Nicoll and B.M. Radke in 1972, and R.S. Nicoll and the author
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in 1978. The surface samples, mostly sandy skeletal micrite-grain calcarenite, calcareous sandstone and calcisiltite, were collected from localities within the measured sections of Veevers & Roberts (1968) on the Burt Range Shelf. All surface samples are designated by the original field locality numbers; e.g., the expression 145/7 indicates locality 7 within measured section 145. The subsurface samples (cores and cuttings), of similar lithofacies as in outcrop, came from several shallow holes drilled by Aquitaine Australia Minerals (AAM) for lead-zinc-silver exploration, on the Burt Range Shelf and Carlton Shelf during the late 1970s and early 1980s. The following account briefly gives the number of localities sampled within each section, and their approximate position within the Buttons Formation. A more detailed list of localities and species determinations is given in the Appendix. Details of the preparation of samples and individual specimens has been provided by Jones (1989, p. 8). Ostracods have been found in 114 samples of the Buttons Formation, of which 97 are from the surface and 17 from the subsurface. The original study (Jones 1968, pp. 44, 45; fig. 6) was based on a collection recovered from 19 samples taken from the type section (105 of Veevers & Roberts 1968; Fig. 2) between 10 ft (3 m) and 860 ft (262 m) above the base, and 8 samples from localities 100/4 (= 144/1), 145/5, 145/7, 145/9, 146/10, 146/11 and 146/13 (of Veevers & Roberts 1968; (Fig. 3; Appendix) in the Eight Mile Creek area. Further ostracod specimens were found in 10 samples collected from the Eight Mile Creek area in 1972 by R.S. Nicoll and B.M. Radke (606/9 to 25). More specimens were found in 60 samples collected by the author in 1978 from the type section (01/10 to 05/48) ranging between 30 m (98 ft) and 231 m (758 ft) above the base (see Appendix). The latter samples were collected from 6 auxiliary sections (01, 02, 03, 04, 05 and 06, Fig. 2; Tables 16-21 Appendix), measured by R.S. Nicoll, and integrated with the original sample localities (Jones 1968) at 50 successive horizons. In subsurface, the Buttons Formation yielded ostracods in 8 core samples from drill hole WBS 4171 (Knox Creek Plain area, Burt Range Shelf), and 9 core samples from drill hole DDH 13 (Carlton Shelf) (see Appendix). TAXONOMIC NOTES Since the first study of ostracods from the Buttons Formation (Jones 1968), more taxa were described based on material collected in 1978 (Jones 1985, 1987, 2004). Examination of the additional material has revealed the presence of more new species and the necessity
AAP Memoir 39 (2010) to revise some of those previously described. Brief taxonomic notes are provided here on the ostracod species previously described from the Buttons Formation, and the Systematic Palaeontology section contains descriptions of species that are either new, revised or in open nomenclature. The classification of Palaeozoic Ostracoda adopted here broadly follows that used and developed by Becker (1990, 2002). The arguments advanced by Becker (1990) and Adamczak (1991) that the Suborder Platycopina has (via the monotiopleurids) a closer affinity to the palaeocopes rather than to the Podocopida are accepted here. The suprafamilial classification of the early (Palaeozoic) platycopines, as used here, broadly follows that of Adamczak (1991) and the manuscripts of that author, published posthumously by Becker (Adamczak 2003a-d; 2004a,b, 2006a-c). Order BEYRICHICOPIDA Pokorný, 1953 [= Palaeocopida Henningsmoen, 1953 (sensu Adamczak 2000)] Suborder PALAEOCOPINA Henningsmoen, 1953 (sensu Becker 1990) Seven palaeocopine species are present in the Buttons Formation, which represent 26% of the total number of ostracod species. Of these, four are referred to the Beyrichioidea (Rhytiobeyrichia waruwa Jones, 1987; Katatona romei Jones, 1985; Notoscapha oepiki Jones, 1985; Parabouchekius martinssoni Jones, 1985), two to the Hollinoidea (Parabolbinella sp. A, sp. B) and one to the Primitiopsoidea (Urftella? sp.). Among the Beyrichioidea, female carapaces of the beyrichiid Rhytiobeyrichia waruwa (Fig. 7A, D) superficially resemble, in lateral view, Kozlowskiella (Illativella) omolonensis Kotschetkova & Tschigova (in Buschmina et al. 1986, pl. 2, fig. 10), the only published illustration of this species. The poor preservation of the Russian species does not allow a confident comparison. There is a slight similarity to Evlanovia tichonovitchi Egorov, 1950 (Egorov 1950, p. 75, pl. 9, figs 1-12; Abushik 1990, p. 137, pl. 74, figs 18, 19), but this species is more elongate, and exhibits kloedenellid dimorphism rather than the beyrichiid dimorphism that is characteristic of the Australian species. The treposellid Katatona romei (Fig. 7B, C; unfigured specimen CPC 16846, locality 02/08), the type species of Katatona Jones, 1985, can be compared to K. acutilobata (Rome 1971). The recent citation of the latter as the type species (Jones 2004, p. 192) is an error, which is corrected herein. Female specimens of K. acutilobata, the only other species known to belong to the
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Figure 4. A-C, Armenites australae Jones, 2004, carapace (juvenile, 1.25L) CPC 16679, right lateral, left lateral, dorsal; D-F, Chamishaella obscura Tschigova, 1977, D, right valve (adult, 1.90L) CPC 16690, right lateral, E, carapace (juvenile, 1.15L) CPC 16694, right lateral, F, carapace (juvenile, 1.55L) CPC 16691, anterior; G-J, Shishaella electa Tschigova, 1977, G, I, carapace (adult male, 2.15L) CPC 16705, right lateral, dorsal, H, J, carapace (adult female, 1.88L) CPC 16706, right lateral, dorsal; K-M, Shishaella petchoraensis Tschigova, 1977, K, carapace (adult male, 1.74L) right lateral, L, carapace (adult female, 1.64L) CPC 16730, left lateral, M, carapace (adult female, 1.68L) CPC 16729, posterior. All scale bars equal 200 microns.
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genus, are distinguished from those of K. romei by their subcircular outline in dorsal and ventral views, and the crumina, which bears 2 or 3 cristae, is broadly rounded at the posterior end. Two other treposellids, Notoscapha oepiki (Fig. 7E, F; unfigured specimen CPC 16847, locality 04/01A) and Parabouchekius martinssoni (Fig. 7G-I; unfigured specimens CPC 16848, locality 105/440; CPC 16849, locality 105/660) are currently monospecific. Descriptions of the new palaeocopine taxa consist of the hollinoid species Parabolbinella sp. A, P. sp. B (Fig. 7J, K), and the primitipsoid species Urftella? sp. (Fig. 8A-O), are provided below. Suborder PLATYCOPINA Sars, 1866 (sensu Adamczak 2000) Six platycopine species are present in the Buttons Formation, which represent 22% of the ostracod species. Of these, two are referred to the Cytherelloidea, within the Cavellinidae [Cavellina sp. A Jones, 1968; Sulcella (Postsulcella) altifrons Jones, 1968], four are referred to the Barychilinoidea, within the Serenididae [Diphyochilina tryphera Jones, 1968; Serenida? alta sp. nov.; Coeloenellina sp. cf. C. fabiformis (Kesling & Kilgore, 1952); and provisionally Indivisia baschkirica Rozhdestvenskaya & Tschigova, 1972 (= Indivisia variolata Zanina, 1960 sensu Jones 1968)]. Descriptions of these platycopine taxa are provided below. Suborder UNCERTAIN (“non-kloedenellaceans” sensu Adamczak 2004a = Knoxitacea Egorov, 1950 sensu Olempska 1999) Six species, representing 22% of the total number of ostracod species, are provisionally placed in suborder uncertain, superfamily unknown. Of these, four are referred to the Geisinidae: Geisina monothele Jones, 1968; Knoxites perplexa (Jones, 1968); Marginia reticulata Jones, 1968; M. venula Jones, 1968; and two to the Beyrichiopsidae: Beyrichiopsis? anogma sp.nov. (= Leptoprimitia sp. A Jones, 1968; Figs 9A-F) and Beyrichiopsis teicherti sp. nov. (Figs 11A-H, J, K; unfigured specimen CPC 16868, locality 04/01A). The geisinids are revised and the beyrichiopsids described below. Suborder UNCERTAIN (Paraparchitoidea) (see also Olempska 2008) Four species are referred to the Paraparchitoidea (Armenites australae Jones, 2004; Chamishaella obscura Tschigova, 1977; Shishaella electa Tschigova, 1977; Shishaella petchoraensis
AAP Memoir 39 (2010) Tschigova, 1977), which represent 15% of the total number of ostracod species. The uncertain systematic position of the Paraparchitoidea (based on the sole family Paraparchitidae) has been recently discussed by Jones (2004, p. 200-202), who provisionally referred the superfamily to the Suborder Paraparchitocopina Gramm in Gramm & Ivanova, 1975. However, it is conceded that its subordinal position is still debatable. Armenites australae (Fig. 4A-C; unfigured specimen CPC 16857, locality 146/10; described by Jones 2004, p. 203, 204, figs 9-11), is morphologically close to A. asiaticus (Buschmina, 1970) in that the cardinal spines are confined to the right valve, and that the dorsal border of the right valve slightly overreaches the straight hinge. It differs from A. asiaticus in the slightly shorter length of the carapace and of the hinge-line. Chamishaella obscura Tschigova, 1977 (Figs 4D-F; described by Jones 2004, p. 205, 207, fig. 13) is characterised by a coarsely punctuate surface, subovate lateral outline, right valve strongly overreaching the left valve along dorsum, and an outward-pointing swelling along venter. Shishaella electa Tschigova, 1977 (Fig. 4G-J; unfigured specimens CPC 16853-16856, localities 105/420, 105/440, 105/450, 04/01A; described by Jones 2004, p. 211-215, figs 17-19) is abundant (N = 300) in the Buttons Formation. Shishaella petchoraensis Tschigova, 1977 (Fig. 4K-M; described by Jones 2004, p. 217-219, fig. 21) is rare (N = 13) in the Buttons Formation, and dimorphism recognised. The pre-adult moults are similar in lateral outline to S. donica (Tschernyschev, 1924) as described by Gurevich (1972, p. 304, pl. 4, figs 1, 2). Order PODOCOPIDA Müller, 1894 Suborder PODOCOPINA Sars, 1866 Four podocopine species are present in the Buttons Formation, representing 15% of the total number of ostracod species. Of these, two are referred to the Bairdioidea, within the Bairdiidae [Bairdia (Bairdia) ordensis (Jones, 1968) and Bairdia (Rectobairdia) aff. philippovae Egorov, 1953] and two are referred to the Bairdiocypridoidea, within the Bairdiocypridiidae [Bashkirina dubitata (Jones, 1968), Cryptocyprois sp. cf. C. subgibberosa Buschmina, 1977]. These podocopines are described in the Systematic Palaeontology section. For the sake of brevity, all references to the above named species given in the following discussions on biostratigraphy, palaeoecology and palaeobiogeography are quoted without the name of the author, or the year the species was introduced.
AAP Memoir 39 (2010) Class UNCERTAIN (Branchiopoda?) Order ERIDOSTRACA Adamczak, 1961 One cryptophyllid species, Cryptophyllus sp. indet., previously reported in the Buttons Formation (Jones 1968), is undescribed in this paper. It is present in 16 out of 50 sampled horizons. Veevers (1969) reported Cryptophyllus in many thin sections as disassociated valves, unlike the ostracods, which have articulated carapaces. BIOSTRATIGRAPHY In all, 27 benthic ostracod species (not counting the eridostracan Cryptophyllus) are present in the Buttons Formation. Of these, 23 occur in the type section (105) of the Ord River in comparison with the 13 originally described (Jones 1968). The stratigraphical distribution of these species is shown in Figure 5. Of the four species not present in the type section, three (Knoxites perplexa, Marginia reticulata, Parabolbinella sp. A) occur in the Eight Mile Creek area in sections (100/4, 144, 145, 146, and 606) and one (Parabolbinella sp. B) occurs subsurface in DDH 13, north of the Pincombe Range (see Appendix). Biozonation Four provisional concurrent range-zones were originally proposed, based upon the overlapping ranges of Sulcella altifrons, Diphyochilina tryphera and Orthobairdia ordensis in the type section (Jones 1968). These range-zones were the Sulcella altifrons Zone, Diphyochilina tryphera Zone, Sulcella altifrons-Orthobairdia ordensis Zone and Orthobairdia ordensis Zone. This working scheme is herein modified by the revision of the described species, and augmented by the addition of other (including new) species. The new scheme is now reduced to three zones, viz., Sulcella (Postsulcella) altifrons Zone, Diphyochilina tryphera Zone and Bairdia (Bairdia) ordensis Zone (Fig. 5). The following account provides definitions of the revised local biozonation, which has been used in earlier biostratigraphic accounts without explanation (e.g., Young 1996, chart 4; Jones 2004, p. 185, fig. 2). The Sulcella (Postsulcella) altifrons Zone, the lowest benthic zone, occupies the lower part of the Buttons Formation (60-350 ft; 18-107 m above the base). Its lower limit is marked by the earliest occurrences of Sulcella (Postsulcella) altifrons, Marginia venula and Shishaella electa. Its upper limit is marked by the earliest occurrence of Diphyochilina tryphera. Below the defined base of the Sulcella (Postsulcella) altifrons Zone, three species occur at 10 ft (3 m) above
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the base. One of these is found in the Sulcella (Postsulcella) altifrons Zone (Beyrichiopsis? anogma sp. nov.), and two (Geisina monothele; Indivisia baschkirica) range into the Sulcella (Postsulcella) altifrons Zone and overlying zones. Other species that first appear in the Sulcella (Postsulcella) altifrons Zone and range into overlying zones are Notoscapha oepiki (30 m), Baschkirina dubitata (45 m), Beyrichiopsis teicherti sp. nov. (52m), Armenites australae, Serenida? alta sp. nov., Cryptocyprois sp. cf. C. subgibberosa (all 60 m), Cavellina sp. A (72 m), Katatona romei (90 m), and Urftella? sp. (91 m). The only species apparently confined to the Zone is Rhytiobeyrichia waruwa (88-93 m). The Diphyochilina tryphera Zone coincides with the interval 350-660 ft (107-200 m), and is a combination of the former Diphyochilina tryphera Zone and Sulcella (P.) altifrons/ Orthobairdia ordensis Zone of Jones (1968). Its lower limit is marked by the earliest occurrence of Diphyochilina tryphera. Species that first appear in the Zone are Parabouchekius martinssoni (113 m), Bairdia (Rectobairdia) aff. philippovae (120 m), Chamishaella obscura (120 m), Shishaella petchoraensis (128 m) and Bairdia (Bairdia) ordensis (128 m). The paraparchitiid Chamishaella obscura is also known in the lower Carboniferous of the Canning Basin, where it occurs just above the first appearance of Siphonodella sulcata (Jones 2004, p. 208). Species that last appear in the Diphyochilina tryphera Zone are Geisina monothele, Sulcella (P.) altifrons, Marginia venula, Notoscapha oepiki, Beyrichiopsis teicherti sp. nov., Armenites australae, Diphyochilina tryphera, Katatona romei and Parabouchekius martinssoni. The Bairdia (Bairdia) ordensis Zone occupies the interval 660-860 ft (200-262 m), and lacks the species diversity of earlier zones. Its lower limit is marked by the last occurrences of Diphyochilina tryphera, Katatona romei and Parabouchekius martinssoni (200 m). The Bairdia (Bairdia) ordensis Zone contains seven species that range up from the lower zones [Bairdia (Bairdia) ordensis, Bairdia (Rectobairdia) aff. philippovae, Cryptocyprois sp. cf. C. subgibberosa, Indivisia baschkirica, Serenida? alta sp. nov., Shishaella electa, Urftella? sp.]. Additionally, Coeloenellina sp. cf. C. fabiformis first occurs within the zone at 228 m above the base of the Buttons Formation. In other sections (e.g., 606) this species occurs in the lower part of the Diphyochilina tryphera Zone. The upper limit of the Bairdia (Bairdia) ordensis Zone in the Buttons Formation is environmentally controlled above 860 ft (262 m). No ostracods have been found in the sandy micrite-granular calcarenite at the top of the fossiliferous part of
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Figure 5. Distribution of benthic ostracod species in the type section (105) of the Buttons Formation.
HEIGHT ABOVE (ft) BASE(m) 1150 350 1100 1000
200 600 500 400 300 200
01/15
100
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the section (900 ft; 274 m). Apart from remains of the plant Leptophloeum (1075 ft; 327.6 m), the sandy and silty dolomite and feldspathic quartz sandstone in the upper 245 ft (75 m) of the type section of the Buttons Formation appears to be unfossiliferous (Jones 1968). A decrease in the amount of carbonate in the top of the Buttons Formation compared with that in the lower Burt Range Formation (Veevers & Roberts 1968, figs 30, 41) suggests a marine regression took place late in the Famennian (Strunian), which can be equated with the Yellow Drum regression in the
Cryptophyllus sp. indet. [Eridostraca]
Shishaella petchoraensis Tschigova, 1977 B. (Rectobairdia) aff. philippovae Egorov, 1953 Bairdia (Bairdia) ordensis Jones, 1968 Coeloenellina cf. fabiformis Kes. & Kilg., 1952
Parabouchekius martinssoni Jones, 1985 Chamishaella obscura Tschigova, 1977
Katatona romei Jones, 1985 Urftella? sp. Diphyochilina tryphera Jones, 1968
Cavellina sp. A. Jones, 1968 Rhytiobeyrichia waruwa Jones, 1987
0
Beyrichiopsis anogma sp. nov. Geisina monothele Jones, 1968 Indivisia baschkirica Roz.& Tsch., 1972
0
Serenida alta sp. nov. Cryptocyprois cf. subgibberosa Bush., 1977
105/100
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Baschkirina dubitata (Jones, 1968) Beyrichiopsis teicherti sp. nov. Armenites australae Jones, 2004
05/18 105/430 105/420 04/01A 105/370
ordensis
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105/660 105/600
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Sulcella altifrons Jones, 1968 Shishaella electa Tschigova, 1977 Marginia venula Jones, 1968 Notoscapha oepiki Jones, 1985
05/42
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tryphera
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altifrons
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Canning Basin. Local correlation From the revised taxonomy and stratigraphic distribution of the ostracod species in the type section, in the Eight-Mile Creek area (e.g., localities 100/4, 145/5 to 145/9, 146/10 to 146/13) and their determinations from additional localities (Section 606) it is apparent that revision is necessary to the earlier work (Jones 1968). Also the determination of ostracod species in drill holes in the Knox Creek Plain area (WBS
AAP Memoir 39 (2010) 4171) and north of the Pincombe Range (DDH 13) demonstrates the upper part of the Buttons Formation exists subsurface in those areas. Section 145 (localities 145/5 to 145/9; an interval of 17 m), where pebbly sandstone and glauconitic calcareous sandstone are exposed, may correlate with an interval near the base of the Diphyochilina tryphera Zone (below 128 m in Section 105), which is equivalent to the base of the former Sulcella altifrons-Orthobairdia ordensis Zone as previously recognised (Jones 1968). The ostracod fauna includes Chamishaella obscura and Coeloenellina sp. cf. C. fabiformis in localities 145/7 and 145/9, but notably the section lacks Bairdia (Bairdia) ordensis. Reasons for the absence of the latter may be environmental, or structural as favoured here, because the upper part of the Buttons Formation is probably missing, due to a faulted contact with the lowest beds of the overlying Burt Range Formation (with Siphonodella sulcata) at locality 145/10, 5 m above locality 9. Section 146 (localities 146/10 to 146/13; an interval of 11 m of sandy skeletal limestone interbedded with pebbly calcareous sandstone) includes the species Bairdia (Bairdia) ordensis, in association with Armenites australae, Diphyochilina tryphera, Katatona romei, Coeloenellina sp. cf. C. fabiformis (Jones 1968, 1985, 2004) and correlates with the range of the Diphyochilina tryphera Zone (107-200 m in Section 105). Also locality 100/4, which includes Sulcella (Postsulcella) altifrons, Katatona romei, Diphyochilina tryphera, Parabouchekius martinssoni, Coeloenellina sp. cf. C. fabiformis and Bairdia (Bairdia) ordensis (Jones 1968, 1985), correlates with this interval. Section 606 (localities 606/9 to 606/25; an interval of about 140 m) correlates with the Diphyochilina tryphera Zone (107-200 m) and, despite the absence of the eponymous species, the co-occurrence of Sulcella (Postsulcella) altifrons and Bairdia (Bairdia) ordensis in locality 606/9 indicates a position low in that interval. Chamishaella obscura is present in localities 606/14 and 606/17. It is noteworthy that the conodont Rhodalepis inornata Druce, 1969 (= “Polylophodonta sp. A of Druce, 1969”), recovered from 606/8 and 606/24, ranges in the type section of the Buttons Formation from 120-250 m above the base (R.S. Nicoll, pers. comm.). WBS 4171, spudded in on black soil in the Knox Creek Plain area, 5 km SE of Sorby Hills, yielded ostracods throughout the interval 26–90 m (see Appendix). The fauna includes both Bairdia (Bairdia) ordensis (26–86 m) and Chamishaella obscura (26–90 m), and these species are
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associated with Shishaella petchoraensis at 74-78 m and 26-34 m. A correlation with the lower part of the Diphyochilina tryphera Zone is indicated. DDH 13, north of the Pincombe Range, yielded ostracods throughout the intervals 81.6–110 m and 145-185 m TD. The dolostone sequence 110-145 m was not examined (see Appendix). The presence of both Diphyochilina tryphera and Bairdia (Bairdia) ordensis (at 110–115 m) indicates a position in the upper part of the Diphyochilina tryphera Zone. Coeloenellina sp. cf. C. fabiformis associated with Diphyochilina tryphera (at 145–150 m) is also within the Diphyochilina tryphera Zone. The Diphyochilina tryphera Zone extends at least to the depth of 150155 m, and possibly to 170-175 m which contains Coeloenellina sp. cf. C. fabiformis. The conodont Rhodalepis inornata Druce, 1969 was recovered from core samples in the intervals 81.6-105 m and 160-165 m (R.S. Nicoll, pers.com.). Age implications The age of the benthic ostracod species of the Buttons Formation is determined here by evaluating their morphological relationship (in terms of conspecificity, or groups of related species) with the stratigraphic ranges of species described from other geographic areas. Most of the ostracod species (67%) of the Buttons Formation indicate a broad Late Devonian (Famennian) to early Carboniferous (Hasterian) age. Species older than this age range are Bairdia (Rectobairdia) philippovae (Frasnian), Urftella? sp. (Givetian-Frasnian) and Coeloenellina sp. cf. C. fabiformis (Givetian); none indicate an age younger than Hasterian. Three of the four species of Paraparchitoidea are considered to be conspecific with those described from extra-Australian sources, viz. Russia and the former USSR. They are Chamishaella obscura, Shishaella electa and S. petchoraensis, originally described by Tschigova (1977) from the Strunianearly Tournaisian (Hasterian) in the Upper Pechora Depression of the East European Platform. Jones (2004) noted that Shishaella electa passes from the Strunian into the Hasterian in both the Bonaparte Basin and the Upper Pechora Depression, and S. petchoraensis is slightly older (Strunian) in the Bonaparte Basin than its occurrence in the Upper Pechora Depression. The genus Armenites Tschigova, 1977, provisionally placed among the Paraparchitoidea (Jones 2004), is also indicative of a late Famennian to early Hasterian age. Armenites australae is closest in morphology to A. asiaticus (Buschmina, 1970), a species present in the Strunian (Lower Tarkhan, II Complex = Fa2d)
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of the Rudnyi Altai, and the Eltsov Depression (Buschmina 1970a, Buschmina et al. 1981), and in the Strunian of the Berchogur, DevonianCarboniferous boundary section, Mugodzhary Mountains, West Kazakhstan (Kotschetkova 1987). Bless et al. (1988) recorded a species of the genus in the late Famennian (Fa 2c) Montfort IV section, Ourthe Valley, Belgium as Armenites sp. (cf. A. compositus Tschigova, 1977 and A. philippovae Tschigova, 1977). Among the Barychilinoidea, one species is conspecific with Indivisia baschkirica from the former USSR. Indivisia baschkirica ranges throughout the upper Famennian (Eletsk to Khovansk) of the East European Platform (Tschigova 1977), and is probably represented in the lower Carboniferous (Hasterian) by I. kazakhstanica Buschmina, 1977a from the Tournaisian Kassin Beds of the Tselinograd region of Kazakhstan (Buschmina 1977a, p. 86, pl. 22, fig. 9), and by I. abyschevaensis (Buschmina, 1965), from the Abyschev beds (Strunian) in the Kuznetsk Basin (Buschmina 1965, p. 77, pl. 3, figs 7, 8, pl. 4, fig. 13), and the Elergetkhyn Suite (Strunian to lower Hasterian) in the Omolon Massif (Buschmina et al. 1986, pl. 6, figs 5,6). These three species are morphologically very similar, and belong to the Indivisia baschkirica species group. Species belonging to the bairdiocypridoidean genus Cryptocyprios Gorak, 1966 are common in rocks that correlate about the DevonianCarboniferous boundary. The species determined as Cryptocyprios sp. cf. C. subgibberosa is morphologically close to C. subgibberosa Buschmina, 1977a, from the lower Kassin Formation, Karaganda Basin, central Kazakhstan, which contains brachiopods of the Mesoplica kassini-Cyrtospirifer sibiricus Zone, and unilocular foraminiferids Bisphaera and Earlandia of early Tournaisian age. The Australian species is also closely related to Cryptocyprios magna Wang, 1988 from the middle praesulcata Zone of the classic Devonian/Carboniferous Nanbiancum section, Guilin, South China. Among the Bairdioidea, Bairdia (Bairdia) ordensis is morphologically close to Bairdia hypsela Rome, 1971, emend. Lethiers, 1975 from the Tn1a of Belgium, and Fa2c-Tn1a of the Avesnois region, northern France. Lethiers (1975) suggested the Australian taxon may be a geographic subspecies of Bairdia hypsela; it certainly belongs to the Bairdia (Bairdia) hypsela species-group, members of which are also present in rocks of Strunian-early Hasterian age in Germany, Poland, North Africa and Kazakhstan (Lethiers 1975; Becker 1987, 1993; Becker & Bless 1990).
AAP Memoir 39 (2010) Some species have stratigraphic ranges short enough to allow the maximum possible age of the Buttons Formation [Late Devonian (Famennian) to early Carboniferous (Hasterian)] to be reduced to Strunian (Fa2d-Tn1a). These include the treposellid Katatona romei and the bairdiocypridid Baschkirina dubitata. Katatona romei is a species related to K. acutilobata (Rome, 1971) from the lower (Tn1a) parts of the Feluy and Onoz sections, Belgium (Jones 1985). Baschkirina dubitata is morphologically closest to Baschkirina microspina Olempska, 1979, from the late Famennian (Wocklumeria Stage, do VI) of the Holy Cross Mountains, Poland (Olempska 1979, p. 123, pl. 26, figs 1a- 2d). Thus, on the basis of the present age assessment of the benthic ostracods it is concluded that the Buttons Formation is probably Strunian (equivalent to Zone DSO 8 of Lethiers 1984), as discussed earlier (Jones 1985). This is further confirmation of the reassessment (R.S. Nicoll, fide Jones 2004) of the conodont described by Druce (1969) as Polylophodonta sp. A, which ranges from 120 m to 250 m in the type section (Jones 1985). This element was thought to indicate an early Famennian (doIIβ-doIII) age (Druce 1969; Roberts et al. 1967, 1972), but it was regarded by Jones (2004) as synonymous with Rhodalepis polylophodontiformis Wang & Yin (1985, pl. 1, figs 9-11) from the neritic facies in the Xiakou section of the Rongxian Formation, Guangxi, where it definitely belongs to the lower to middle praesulcata Zone (Wang & Yin 1985). R.S. Nicoll regards Rhodalepis polylophodontiformis as a junior synonym of the inaptly named type species of Rhodalepis (R. inornata Druce, 1969). The type specimens of R. inornata bear the same delicate subconcentric ribbing on the platform as R. polylophodontiformis, but this ornamentation is not shown in Druce’s figures (pl. 38, figs 1b, 2b), probably because this feature was completely obscured on the specimens by ammonium chloride prior to photography. PALAEOECOLOGY The Buttons Formation, a mixed carbonate/ clastic lithofacies, was deposited in shallow warm lagoons on the landward side of a reef complex that now constitutes the Garimala Limestone, the uppermost unit of the Ningbing Group (Mory & Beere 1988). During the Famennian the Pincombe (Precambrian) Inlier was probably an island (Veevers & Roberts 1968), surrounded by lagoons on the southern (Burt Range Shelf) and northern (Carlton Shelf) margins. Most of the ostracod-bearing horizons are in the dominant lithofacies, a sandy skeletal micritegrained calcarenite, with interbedded calcareous
AAP Memoir 39 (2010) sandstone and calcisiltite that ranges from 26 m to 262 m above the base of the type section (105). The ostracod assemblages are characterised by intervals of low-diversity faunas (1-5 species) interrupted by four successive intervals of highdiversity faunas (6-11 species) at 93 m, 113-120 m, 126-131 m and 183 m above the base. These intervals of high-diversity faunas are more likely to represent sampling bias, rather than maximum flooding surfaces. The ostracod faunas are dominated by palaeocopines (26% of total number of species), consisting of six, possibly seven species, of which the treposellids (Katatona, Notoscapha, Parabouchekius) are numerically common, and the remaining species (of Parabolbina, Rhytiobeyrichia and Urftella?) are rare. Other dominant groups are the platycopines (22% of the total number of species) and “nonkloedenellaceans” sensu Adamczak 2004a (22% of total number of species). Among the platycopines, Diphyochilina, Sulcella and Indivisia are numerically abundant and Cavellina, Coeloenellina and Serenida are rare. The “nonkloedenellaceans” (four geisinids, and two beyrichiopsids) are relatively common. The paraparchitoids are represented by four species (15% of the total number of species), of which only Shishaella electa is numerically abundant, and Armenites australae is common. The podocopines are represented by four species (15% of the total number of species), of which only Bairdia (Bairdia) ordensis and Baschkirina dubitata are numerically abundant. The eridostracan Cryptophyllus occurs in 16 of a total of 50 horizons studied in the type section. The ostracod assemblages of the Eight Mile Creek area are similar to those of the type section, but lack palaeocopines (except for Parabolbinella, absent in the type section), Cryptocyprois and Serenida are also absent, and the eridostracan Cryptophyllus is only present in one locality (146/10). Additionally, the Eight Mile Creek fauna is characterised by the presence of Knoxites perplexa, Marginia reticulata, species of Parabolbinella (all absent in the type section) and considerably more individuals of Coeloenellina sp. cf. C. fabiformis. On the basis of a detailed petrographic and computer analysis, Veevers (1969) distinguished the carbonate rocks of the type section as outer lagoonal and those of the Eight Mile Creek area as inner lagoonal. The differences between the ostracod biofacies may reflect this difference in lithofacies. Species of the brachiopod Cyrtospirifer also may reflect this difference, with records of C. ningbingensis in the type section (224 m, 250 m, 262 m) and C. depressus in the Eight Mile Creek area (145/5)
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and at the depth of 95-100 m in DDH 13 (Roberts 1971, 1985). Modern subfossil ostracod assemblages commonly contain species from several different biotopes, some indigenous and others reworked, transported from foreign biofacies (e.g., Isuka & Kaesler 1986). Thus, it is necessary to determine whether or not post-mortem transportation has taken place (Kilenyi 1971; De Deckker 2002). Veevers (1969, p. 67), on the basis of a principal co-ordinate (or Q-factor) analysis of associations among the modal and chemical attributes of limestone samples taken from the Upper Devonian and Carboniferous carbonate platform sequence of the Bonaparte Basin, suggested that the ostracods may have lived in a different environment from the other skeletal organisms. Although there is some evidence to support this notion, based on paraparchitids in samples collected from the lower Tournaisian Burt Range Formation (Jones 2004), there is evidence to the contrary, based on ostracod samples collected from the type section of the Buttons Formation. All picked ostracod assemblages consist of articulated carapaces; no disarticulated valves were found, and the size distribution of several species [viz., Indivisia baschkirica (Jones, 1968, fig. 13) from sample 105/170; Diphyochilina tryphera (Jones, 1968, fig. 18) from sample 105/420; and Shishaella electa (Jones, 2004, fig 19) and Armenites australae (Jones, 2004, fig. 11) both from sample 04/01A.] are based on a mixture of adults and juveniles which may be interpreted as low energy thanatocoenoses, representing indigenous faunas, rather than higher energy taphocoenoses with post-mortem transport and size sorting (see note by Williams et al. 2006 “that the terms biocoenosis and thanatocoenosis have often been used inaccurately in the ostracod literature; see Boomer et al. 2003 for discussion and definitions)”. The ostracod faunas of the type section are dominated by palaeocopines (26% of total number of species), platycopines (22%) and “non-kloedenellaceans” sensu Adamczak (2004a) (22%). Paraparchitoids and podocopines are each represented by 15% of the total number of species. The eridostracan Cryptophyllus occurs in 16 of a total of 50 horizons studied in the type section. This proportion of ostracod groups is broadly compatible with those of the Eifelian Mega-Assemblage sensu Casier (2004), which is characterised by the presence of palaeocopid, platycopid, metacopid, podocopid, and more rarely of leperditicopid ostracods and Eridostraca. It is indicative of shallow, generally well oxygenated environments, and the relative proportions of these ostracod groups permit recognition of several
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Ic
V IIIc
IV Ib Ia IIIb II
IIIa GONDWANA
Figure 6. Ostracod palaeozoogeography during Famennian time (Lethiers 1983) plotted on the Scotese & McKerrow (1990) reconstruction for the Famennian, showing five provinces recognized by Lethiers (1983, fig.5): I Serenida Province with three domains: Ia with regina (western Canada), Ib with primula (Russian Platform), Ic with Moorites (Kuznetsk Basin); II Graphiadactyllis Province (Appalachian region of North America); III hypsela-Rectonaria Province with three domains: IIIa with gosseleti-beugniesi (north Africa, western and central Europe), IIIb with venula-reticulata (northwestern Australia), IIIc Kazakhstan Province; IV sinensis Province (SE Asia, including South China); V solita Province (eastern Siberia). Arrows denote the supposed ocean circulation (Jones 2004).
assemblages from lagoonal environments below storm wave base, which are controlled prinicipally by the energy, the salinity, and the nature of the substrate (Casier et al. 2006, p. 824). The absence of the metacopids in the type section is possibly because they were adapted to living in an open marine, low energy environment compared to the more restricted (lagoonal) environment of the Buttons Formation. However, Eifelian Mega-Assemblages, without metacopids, have been recognised in the Devonian-Carboniferous transitional strata at Avenois in northern France (Casier & Préat 2003), and the Chanxhe and Rivage sections in the Dinant Basin, Belgium (Casier et al. 2005). In addition to ostracods, the presence of calcareous algae and foraminiferids, conodonts, brachiopods, corals, stromatoporoids and crinoids supports the inference that the Buttons Formation
was deposited in shallow, warm water (within the photic zone) off-shore, and the presence of charophytes, megaplants and miospores indicate proximity to land. A change in the composition of faunal groups at about 120 m in the type section appears to suggest a general change in salinity. Below this stratigraphic level there are no corals, stromatoporoids or crinoids and a paucity of calcareous algae (e.g., Parachaetetes johnstoni in 105/320). An abundance of microconchid (‘Spirorbis’) tubes at 30 m implies brackish or hypersaline, not necessarily fully marine, conditions (see Taylor & Vinn 2006). Additionally, the charophyte cf. Quasiumbella rotunda (Bykova, 1955) (Veevers 1970) [= Quasiumbella saccamminiformis (Bykova, 1955) (Edgell 2003)] present between 30 m and 128 m, may represent brackish conditions, or could have been washed into a marine milieu during intervals of terrigenous
AAP Memoir 39 (2010) incursions. The presence of lingulate brachiopods (52 m) and Leptophloeum plant fragments (52 m, 107 m, 113 m) indicates proximity to land. Above 128 m, marine influences become stronger with the appearance of corals, stromatoporoids, crinoids and increasing diversity of calcareous algae (Girvanella staminea, G. wetheredii, G. problematica, G. ducii, Kamaena sp., Ortonella aff. O. tenuissima, Parachaetetes regularis, Bevocastria conglobata (Mamet & Roux 1983; Veevers 1970). A possible increase in salinity is indicated by the appearance of typical stenohaline marine bairdoids B. (Bairdia) ordensis and B. (Rectobairdia) aff. philippovae at 128 m, and of brachiopods (Leioproductus buttonensis at 160 m and Cyrtospirifer ninbingensis at 224 m; Roberts 1971). PALAEOZOOGEOGRAPHY The benthic ostracod fauna of the Buttons Formation is highly diversified, consisting mainly of cosmopolitan genera (Armenites, Bairdia, Baschkirina, Beyrichiopsis, Cavellina, Chamishaella, Coeloenellina, Cryptocyprois, Geisina, Indivisia, Knoxites, Marginia, Parabolbinella, Shishaella and Sulcella), many of which are either conspecific with, or closely related to, those recorded from Europe, Russia, Kazakhstan, South China and North America. The distribution of a few genera can be considered as provincial [Diphyochilina, in the early Famennian of Baschkiria (Rozhdestvenskaya 1972); Katatona, in the Strunian of Belgium (Jones 1985); Serenida, in the Late Devonian of the East European Platform and western Canada (Rozhdestvenskaya 1972; Lethiers 1981, 1983), and Urftella? in the late Middle Devonian of Germany (Becker 1970)]. Other genera, in the present state of knowledge, may be endemic, viz., treposellids (Notoscapha, Parabouchekius) and the beyrichiid Rhytiobeyrichia (Jones 1985, 1987). Of these, Parabouchekius is morphologically similar to Bouchekius Rozhdestvenskaya, 1972, a treposellid genus present in the late Famennian of Russia (Omolon Massif) and Belgium (Jones 1985). Ostracod species in the Buttons Formation that are conspecific or in the same ‘speciesgroup’ in extra-Australian localities are discussed below; they include species belonging to Paraparchitoidea, Indivisiidae and Bairdiidae. The presence of three paraparchitoidean species, Chamishaella obscura, Shishaella electa and S. petchoraensis in the Buttons Formation indicate palaeobiogeographic links with the Laurentia-Baltica, Kazakhstan and Siberia blocks (Jones 2004). These species were previously described from the Strunian-early Tournaisian (Hasterian) of the East European
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Platform (Upper Petchora Depression; Tschigova 1977). Shishaella electa is also reported from the early Tournaisian (Hasterian) of Belgium (Tschigova 1977) and South China (Wang 1988). The close morphology of Armenites australae Jones, 2004 and A. asiaticus (Buschmina, 1970a), mentioned above, and the association of A. asiaticus with Chamishaella obscura in Strunian sections in the Rudnyi Altai, and the Eltsov Depression of Siberia (Buschmina 1970a, Buschmina et al. 1981), and in the Strunian of the Berchogur, Devonian-Carboniferous boundary section in the Mugodzhary Mountains of Kazakstan (Kotschetkova & Janbulatova 1987), indicates a palaeobiogeographic link between the Siberian and Kazakhstan blocks and northeastern Gondwana. The genus Armenites is characteristic of the late Famennian-early Hastarian rocks on the eastern margin of the Laurentia-Baltica Plate, and is represented by three other species in the Upper Pechora Depression (A. philippovae Tschigova, 1977; A. compositus Tschigova, 1977; A. quaesitus Tschigova, 1977). During the early and middle Tournaisian (Hastarian) there was a greater diversity, and a wider distribution of paraparchitoid species between the Bonaparte Basin, South China, Kazakhstan, Siberia and eastern Laurentia-Baltica (Jones 2004). Indivisia baschkirica Rozhdestvenskaya & Tschigova, 1977 (upper Famennian of the East European Platform), and the conjunct species I. kazakhstanica Buschmina, 1977 and I. abyschevaensis (Buschmina, 1965) possibly belong to the same species group. Thus, the geographic distribution of the Indivisia baschkirica species group extends from the East European Platform to the lower Tournaisian Kassin Beds of central Kazakhstan (Buschmina 1977a), the Strunian Abyschev beds in the Kuznetsk Basin (Buschmina 1965) and Strunian to lower Hasterian Elergetkhyn Suite in the Omolon Massif (Buschmina et al. 1986). This species group possibly extends to western Canada, where I. baschkirica has been described from upper Famennian rocks (Lethiers 1981). Bairdia (Bairdia) ordensis is of palaeobiogeographic importance because of its close morphological relationship to Bairdia hypsela Rome, 1971 as emended by Lethiers (1975), from the Strunian of Belgium and northern France. Lethiers (1975) suggested that both taxa may be regarded as geographic subspecies, and noted the presence of closely related species in the latest Devonian (do VI) of Poland and Kazakhstan. The palaeozoogeographic distribution of benthic ostracods during the Late Devonian and early Carboniferous has been explained in terms of migration, ocean currents and genetic exchange
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along juxtaposed shallow shelves of the adjacent blocks of Gondwana and Laurentia-Baltica (Jones 2004). Living benthic ostracods have no known pelagic larval stage, and their ontogeny normally proceeds within a single biotope (Elofson 1941; and references given by Schallreuter & Siveter 1985). Thus, it is reasonable to assume that marine benthic ostracod species of the Late Devonian and early Carboniferous, like those living today, lacked a pelagic larval stage and could not cross deep oceanic barriers (Jones 2004). However, the observed zoogeographic links of the paraparchitoids, indivisiids and bairdiids suggest that they could have migrated during transgressive pulses along juxtaposed shallow shelves of the adjacent blocks of Siberia, Laurentia-Baltica and Kazakhstan. Moreover, these links indicate that by the latest Devonian the shallow shelves of the western part of Gondwana and Baltica were close enough to permit exchange of genetic material. This exchange, facilitated by southern anticlockwise ocean currents (Fig. 6), would have permitted the migration of species along the isolated terranes of the southern shelf margin of Palaeotethys as far as northwestern Australia. A similar genetic exchange may have allowed the migration of species in the northern hemisphere from Baltica, Kazakhstan and Siberia, by northern clockwise ocean currents along the continental margins of the Tarim, North China and South China Plates. Certainly, a strong provincial link probably existed between the South China Plate and northwestern Australia within the eastern end of the palaeotethyan equatorial belt during the early Carboniferous (Jones 2000a). The above palaeozoogeographic model can be compared with the earlier synthesis of ostracod palaeobiogeography during the Late Devonian (Lethiers 1983a). The provinces distinguished by Lethiers (1983a) appear well founded for the Late Devonian ostracod data base then available (Fig. 6). It is of interest to see to what extent the Lethiers (1983a) model for the Famennian is changed by considering later papers which describe Ostracoda of that age, and especially those from areas of limited coverage in the original data base [e.g., western Kazakhstan (Kotschetkova & Janbulatova 1987); Omolon Massif (Buschmina et al. 1986); South China (Wang 1988, Coen 1996)]. Lethiers (1983a) accommodated the benthic ostracod fauna of the Buttons Formation within his Province (III) of hypsela-Rectonaria which extends from North Africa, Spain, France, Belgium, Poland, Turkey, Iran, Kazakhstan to northwestern Australia. The eponymous taxon Bairdia hypsela, and its relationship to B. ordensis has been discussed previously. The Buttons
AAP Memoir 39 (2010) Formation, however, contains neither Rectonaria, nor any spinose representatives of the Thüringer Ökotyp of Becker (in Bandel & Becker 1975) that are characteristic of open-marine, low energy palaeoenvironments. Lethiers noted that the presence of numerous Cryptophyllus in Belgium, Turkey and Australia indicated a lagoonal or restricted marine environment. He divided the hypsela-Rectonaria Province (III) into three domains: IIIa Domain of gosseleti-beugniesi on the western margins of Palaeotethys, IIIb Domain of venula-reticulata in northwestern Australia and IIIc Domain of Kazakhstan. The present restudy of the benthic ostracods of the Buttons Formation supports the views of Lethiers (1983a, fig.5) with respect to the degree of faunal relationships between the three domains of his hypsela-Rectonaria Province. It shows that his Domain of venula-reticulata of that province contains more cosmopolitan taxa, i.e, taxa previously described from his Serenida Province (I), which extends from western Canada to the Kuznetsk Basin. These taxa include Indivisia baschkirica and the genus Serenida, present in all three domains of the Serenida Province (Ia Domain of regina in western Canada; Ib Domain of primula in the East European Platform, and western Urals; and Ic Domain of Moorites in the Kuznetsk Basin). The Paraparchitoidea of the Buttons Formation have strong links with the Ib Domain of primula and Ic Domain of Moorites, but none with the Ia Domain of regina (Jones 2004; Lethiers 1981). The genus Cryptocyprois has links with the Donetz Basin (IIIa Domain of gosseleti-beugniesi), Karaganda Basin (IIIc Domain of Kazakhstan), Rudnyi Altai (Ic Domain of Moorites) and South China (Province IV of sinensis). Lethiers (1983, fig. 5) depicted his Famennian Province of sinensis (IV) of SE Asia (including South China) as isolated, without faunal exchange with other provinces. In a later study, Wang (1988) described an ostracod assemblage within the middle to upper praesulcata Zones in the DCB beds of the Nanbiancun section, consisting of many cosmopolitan genera including Bairdia, Bouckaertites, Cryptocyprois and Shishaella. At the species level, the presence of Bairdia hexagona, B. quartziana and Bouckaertites komiensis indicates a strong link with the Upper Devonian of the East European Platform, and the presence of Bairdia moreyi indicates a North American influence, which is more apparent in the early Carboniferous (sulcata to crenulata Zones) ostracod assemblage in the upper part of the Nanbiancun section, Guilin, South China. Lethiers’ Province of solita (V) in eastern Siberia is loosely defined, and is of early
AAP Memoir 39 (2010) Carboniferous age. Bairdia solita Buschmina, 1970a, presumably the source of the name of the province, was described from an extremely diverse ostracod assemblage in the upper Tournaisian Bastakh suite, Verkhoiansk Basin, northern Kharaulakh region (Buschmina 1970b). Bairdia solita was also reported in the early Carboniferous ostracod fauna described from the middle Tournaisian part of the Kamenka section of the Kolyma Massif (Buschmina 1975). Devonian (late Famennian) ostracod assemblages in northeastern Russia were later described from the Upper Devonian (late Famennian) parts of the Dozhdlivogo section of the Kolyma Massif (Buschmina 1979), and sections in the Perevalny suite of the Omolon Massif (Buschmina et al. 1986) respectively. CONCLUSIONS The benthic ostracod fauna of the Buttons Formation of the onshore Bonaparte Basin is re-evaluated on the basis of additional material, and updated in terms of recent studies of Palaeozoic ostracod taxonomy in order to provide a more complete account of their biostratigraphy, age implications, palaeoecology and palaeozoogeography. The fauna is considerably more diverse than was originally thought, and consists of 27 species (not counting the eridostracan Cryptophyllus). Of these, 7 species (26%) are referred to palaeocopine genera (Katatona, Notoscapha, Parabouchekius, Parabolbinella, Rhytiobeyrichia and Urftella?). Six species (22%) are referred to platycopine s.l. genera (Cavellina, Sulcella, Diphyochilina, Serenida, Coeloenellina and Indivisia). Six species (22%) are referred to genera of the group “non-kloedenellaceans” sensu Adamczak (2004a) (Geisina, Knoxites, Marginia and Beyrichiopsis). Four species (15%) are referred to the paraparchitoidean genera (Chamishaella, Shishaella and Armenites). Four podocopine species (15%) are referred to the bairdioidean genera [Bairdia (Bairdia), Bairdia (Rectobairdia), Baschkirina and Cryptocyprois]. The four provisional concurrent range-zones originally proposed for the Buttons Formation, based on the type section (Jones 1968) along the Ord River, are revised and reduced to three biozones - Sulcella (Postsulcella) altifrons Zone, Diphyochilina tryphera Zone and Bairdia (Bairdia) ordensis Zone, which are used for local correlation of outcrops in the Eight Mile Creek area and subsurface sections in the Knox Creek Plain area and north of the Pincombe Range. The age of the benthic ostracod fauna of the Buttons Formation, as presently described, is interpreted by assessing the morphological
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relationship of taxa described from other geographic areas, and their stratigraphic ranges. The presence of taxa which are conspecific, or at least related to the same species-group, in a more diverse fauna, has permitted a greater resolution of the age of the Buttons Formation compared to the original study 42 years ago (Jones 1968). Most of the ostracod species (67%) of the Buttons Formation indicate a general Late Devonian (Famennian) to early Carboniferous (Hasterian) age; notable examples are: (a) the Indivisia baschkirica species-group; (b) the paraparchitoidean species Chamishaella obscura, Shishaella electa and S. petchoraensis, and the genus Armenites; (c) Bairdia (Bairdia) ordensis which belongs to the Bairdia (Bairdia) hypsela species-group; and (d) the genus Cryptocyprios. Some species have stratigraphic ranges short enough to allow a finer resolution for the age of the Buttons Formation, i.e., Strunian (Fa2d-Tn1a), viz., Katatona romei and Baschkirina dubitata. It is concluded that the overall age of the Buttons Formation is probably Strunian, which is further confirmed by the presence of the conodont platform element Rhodalepis inornata Druce, 1969 (R.S. Nicoll, fide Jones 2004), a name that takes priority over the junior synonym Rhodalepis polylophodontiformis Wang & Yin (1985, pl. 1, figs 9-11) from the lower to middle praesulcata Zone of the Rongxian Formation, Guangxi, South China (Wang & Yin 1985). The ostracod palaeoecology is consistent with the accepted scenerio that the Buttons Formation, a mixed carbonate/clastic lithofacies, was deposited in shallow warm lagoons on the landward side of a reef complex (Ningbing Group) that now constitutes the Garimala Limestone (Veevers & Roberts 1968; Mory & Beere 1988). Most of the ostracod-bearing horizons are in the dominant lithofacies, a sandy skeletal micritegrained calcarenite, with interbedded calcareous sandstone and calcisiltite that ranges from 26 m to 262 m above the base of the type section (105). The ostracod assemblages are characterised by intervals of low-diversity faunas (1-5 species) interrupted by four successive intervals of highdiversity faunas (6-11 species) at 93 m, 113-120 m, 126-131 m and 183 m above the base. These intervals of high-diversity faunas are more likely to represent sampling bias, rather than maximum flooding surfaces. All picked ostracod assemblages consist of articulated carapaces; no disarticulated valves were found, and the size distribution of several species (viz., Indivisia baschkiria, Diphyochilina tryphera, Shishaella electa and Armenites australae) are based on a mixture of adults and juveniles which may be interpreted as low energy
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Figure 7. A, D, Rhytiobeyrichia waruwa Jones, 1987, carapace (female, 1.36L) CPC 25334, right lateral and ventral; B, C, Katatona romei Jones, 1985, carapace (female, 0.55L) Holotype CPC 7058, right lateral and dorsal; E, F, Notoscapha oepiki Jones, 1985, carapace (female, 0.60L) Holotype CPC 24651, right lateral and anterior; G-I, Parabouchekius martinssoni Jones, 1985, carapace (female, 0.55L) Holotype CPC 24656, right lateral, ventral and posterior; J, Parabolbinella sp. A, carapace (juvenile, 0.93L) CPC 16802, left lateral; K, Parabolbinella sp. B, right valve (juvenile, 1.05L) CPC 16803, lateral.
thanatocoenoses, representing indigenous faunas, rather than higher energy taphocoenoses with post-mortem transport and size sorting. The proportion of ostracod groups in the type section is broadly compatible with the Eifelian Mega-Assemblage sensu Casier (2004). This ostracod assemblage is characterised by the presence of palaeocopids, platycopids, metacopids, podocopids and, more rarely, leperditicopids and Eridostraca. It is indicative of shallow, generally well oxygenated environments, and the relative proportions of these ostracod
groups permit recognition of several assemblages from lagoonal environments below storm wave base, which are controlled principally by the energy, the salinity, and the nature of the substrate (Casier et al. 2006, p. 824). In terms of palaeozoogeography the latest Devonian (Strunian) benthic ostracod fauna of the Bonaparte Basin consists mainly of cosmopolitan genera, with strong zoogeographic links with the western margins of Palaeotethys (North Africa, Spain, France, Belgium, Poland), the East European Platform and Kazakhstan. There are
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AAP Memoir 39 (2010) weaker links with South China, Northeast Russia (Omolon Massif) and the Cordilleran Province of North America. Benthic ostracods, lacking a pelagic larval stage, could not have crossed deep oceanic barriers. Thus the zoogeographic links probably indicate that the shallow shelves of the western part of Gondwana and LaurentiaBaltica were close enough to permit genetic exchange and migration during transgressive pulses, along juxtaposed shallow shelves of the adjacent blocks of Gondwana and LaurentiaBaltica. A similar connection probably existed between the South China Plate and northwestern Australia, via terranes within the eastern end of the palaeotethyan equatorial belt. The scheme of Famennian ostracod palaeobiogeography advanced by Lethiers (1983a) is sufficiently robust to accommodate these new data for his hypsela-Rectonaria Province III (if adjusted for a restricted-marine, low energy environment). The Buttons Formation ostracod fauna also has strong links with his Serenida Province I, except with the regina Domain Ia (western Canada) where the links are weaker. SYSTEMATIC PALAEONTOLOGY The terminology of the external shell morphology follows Kesling (1951), Jaanusson (1957) and Sohn (1971), and that of the internal shell morphology is after Adamczak (1976) and Olempska (1999). The following abbreviations are used below: c = carapace; LV = left valve; RV = right valve; h = heteromorph; t = tecnomorph; juv = juvenile; L>R = left valve overlapping (or overreaching) right valve; R>L = right valve overlapping (or overreaching) left valve; L = length; H = height; W = width; l = length of hingeline; H/L = height/length ratio; W/L = width/length ratio; W/H = width/height ratio; l/L = length of hingeline/ carapace length ratio; A = presumed adult stage; A-1, A-2, A-3, A-4 etc = consecutive pre-adult instar stages; AMS = adductor muscle scar. All measurements are given in millimetres. Phylum CRUSTACEA Brünnich, 1772 Class OSTRACODA Latreille, 1802 Order BEYRICHICOPIDA Pokorný, 1953 [= Order Palaeocopida Henningsmoen, 1953] Suborder PALAEOCOPINA Henningsmoen, 1953 [including Binodicopina Schallreuter, 1972] Superfamily HOLLINOIDEA Swartz, 1936 Family HOLLINIDAE Swartz, 1936 Parabolbinella Adamczak, 1968 Type species. Parabolbinella postaculeata
Adamczak, 1968, p. 53-5 (by original designation); Eifelian, Skaly Formation, Poland. Diagnosis (after Bless & Jordan 1971, p. 880). Complex bilobate. Tecnomorphs with two adventral spurs. Heteromorphs possess adventral structures consisting of an anteriorly developed frill and a posteroventral spur. Parabolbinella sp. A (Fig. 7J ) Material. 1 carapace (juvenile) - CPC 16802 from locality 606/10, Buttons Formation of Eight Mile Creek area. Description. Outline preplete, subquadrate in lateral view. Hinge-margin straight, anterior cardinal angle 122º; posterior cardinal angle 95º. Postadductorial (L3) lobe relatively small (0.20 mm in diameter), bulbous, not extending as far as the hinge-margin. Preadductorial (L2) lobe is small, bulbous and clearly separated from the other lateral elements of the valve. Adductorial sulcus (S2) deep, relatively wide, extending to the mid-height position. The marginal structure consists of a row of tubercles along the free margin. Two adventral spurs are present in the anteroventral and posteroventral parts of the valve. Surface papillose. Dimensions 0.93L, 0.53H, 0.40W (+L3), 0.57 H/L Remarks. This species cannot be properly defined until better preserved material is found. Parabolbinella sp. B (Fig. 7K) Material. 1RV (juvenile), CPC 16803 from 155 m in core taken from the Buttons Formation in bore DDH 13, about 4 km NE of Jeremiah Hills. Description. Outline preplete, subelongate in lateral view. Hinge margin long, straight; anterior cardinal angle 95º; posterior cardinal angle 75º. Postadductorial (L3) lobe relatively small (0.20 mm in diameter), bulbous, not extending above the hinge margin. L3 extends obliquely in an anteroventral direction, imperceptibly joining the ventral lobe. Adductorial sulcus (S2) deep, relatively wide, extending obliquely to the midheight position. Preadductorial (L2) lobe small distinct knob, separated from the anterior part of the valve by a shallow anterior (S1) sulcus that extends to about 1/4H. The marginal structure consists of a row of tubercles along the free margin. Adventral spurs broken, but the two bases of the spurs can be seen in the anteroventral and posteroventral parts of the valve. Surface papillose. Dimensions 1.05L, 0.48H, 0.40W,
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Figure 8. A-O, Urftella? sp. A, E, carapace (juvenile, 0.60L) CPC 16808, left lateral, dorsal; B, C, F, carapace (juvenile, 0.58L) CPC 16810, left lateral, posterior, ventral; H, I, carapace (juvenile, 0.60L) CPC 16809, left lateral, posterior; D, G, carapace (juvenile, 0.77L) CPC 16807, posterior, right lateral; J, left valve (male, 1.30L) CPC 16806, ventral; K, L, carapace (female, 1.30L) CPC 16805, ventral, right lateral; M, N, O, carapace (male, 1.30L) CPC 16804, posterior, right lateral and detail of posteroventral margin.
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AAP Memoir 39 (2010) 0.46H/L Remarks. This species is easily distinguished from Parabolbinella sp. A by its relatively longer domicilium, oblique adductorial sulcus (S2), and the greater radius of curvature of the posteroventral margin. Superfamily PRIMITIOPSOIDEA Swartz, 1936 Diagnosis. (Adamczak 2005a, p. 25) “Palaeocopina consistently with RV over LV overlap, showing variable shape and surface ornamentation of carapace; velar structures dimorphic, present only in heteromorphs, or absent; velar structure produces, in posterior part of heteromorphic carapaces, the dolon which may be closed externally (in general, forming ‘false’ brood pouch), be widely open or reduced to posteroventral spurs; perimarginal structure present on the posterior valve wall in heteromorphs; hinge structure with sockets and teeth; right valve always larger; adductor muscle scar pattern random-aggregate; ‘infold-like’ structures described in some species. Ordovician– Permian; world–wide.” Remarks. Adamczak (2005a) emphasised the homogeneous nature of the Primitiopsoidea (Primitiopsacea) as a group, “sharply delimited morphologically from other palaeocopine superfamilies”. Several classification schemes, some radically different, have been proposed for this superfamily (e.g., Martinsson 1960; Adamczak 1968; Becker 1970; Melnikova 1979; Wang 1979, 1982; Polenova 1982; Adamczak & Becker 1983; Schallreuter 1986; Abushik 1987, 1990); these have been discussed by Adamczak & Coen (1992), and more recently by Adamczak (2005a, b). Adamczak’s revision of mid-Palaeozoic Primitiopsoidea (Adamczak 1968, 2005a, b) is followed here because it is based on the most recent critical evaluation of type material. Based on different developmental trends in morphology, viz., velar structure being widely open, more or less distinct or totally reduced, and the appearance of reticulation patterns, and longitudinal ridges. Adamczak (2005b, p. 162) cautiously distinguished four distinct groups of genera, informally named: “Clavofabella group”, “Lysogorella/Perunus (sub)group”, “Clavofabellina group” and “Parapribylites group”, without proposing a formal subfamilial division. Thus, all primitiopsoids were retained (pending further evidence) in a single family, the Primitiopsidae Swartz, 1936. This conservative approach provides, at least to my satisfaction, a
reliable framework for discussions (e.g., Becker & Braun 2006), and for future proposals of primitiopsoid phylogeny. The ‘infold-like structures’ in the above diagnosis refer to the thickened internal structures developed along the free margin of ostracod valves. The interpretation of these structures in palaeocopine ostracods, whether or not they represent a calcified inner lamella (= duplicature), has been discussed by many authors (e.g., Gramm 1984, 1988; Olempska 1999; Becker & Adamczak 2002). A duplicature has been suggested by Gramm (op. cit.) for some primitiopsids, but could not be confirmed in thin sections of primitiopsid genera studied by Adamczak (2005a). Family PRIMITIOPSIDAE Swartz, 1936 Diagnosis. (Adamczak 2005a, p. 29) “Primitiopsacea with perimarginal structure (ridge or tubercles); velar structure – if present at all – mostly dimorphic, with heteromorphs showing dolonal flanges posteriorly; adductor muscle scars consisting of numerous, aggregate spots; lateral carapace outline preplete-amplete, occasionally postplete; carapace smooth to ornamented. Ordovician–Permian; world–wide.” Remarks. See ‘Diagnosis and remarks’ of Becker & Braun (2006, p. 278). In the Bonaparte Basin the Primitiopsidae are represented by six species in the informal “Parapribylites group”of Adamczak (2005b): Parapribylites “hanaicus” sensu Jones 1968) in the Late Devonian (Frasnian), Coryellina excaudata Jones, 1989 (a possible junior synonym of C. alba Kotschetkova in Kotschetkova & Janbulatova, 1987), C. robertsi Jones, 1989 and C. cesarensis Crasquin, 1985 in the Tournaisian, and Selebratina serotina Jones, 1989 and Primitiopsacean sp. A of Jones, 1989) in the Visean. The last two taxa probably belong to Guerichiella Adamczak, 1968 (see Olempska 1999). Urftella Becker, 1970 Type species. Urftella adamczaki Becker, 1970, p. 57 (by original designation); Middle Devonian (Givetian), Sötenicher Mulde, N-Eifel, Germany. Diagnosis. (Adamczak 2005a, b) Primitiopsidae of “Clavofabellina group” with elongate rectangular carapace outline, velar structures totally lacking; comparatively distinct perimarginal ridge developed in heteromorphs. Remarks. The monospecific Urftella differs from
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CPC 16804 h CPC 16805 h CPC16806 hLV CPC 16807 A-2 CPC 16808 A-3 CPC 16809 A-3 CPC 16810 A-3
L
H
W
H/L
W/H
1.3 1.3 1.3 0.77 0.60 0.60 0.58
0.80 0.80 0.80 0.50 0.39 0.38 0.35
0.80 0.85 0.42 0.50 0.40 0.35 0.33
0.62 0.62 0.62 0.65 0.65 0.63 0.61
1.00 02/09 8M,N,O 1.06 02/09 8K,L 1.05 02/09 8J 1.00 02/09 8D,G 1.03 04/01A 8A,E 0.92 04/01A 8H,I 0.93 04/01A 8B,C,F
the similar Buregia Zaspelova in Polenova, 1953 (type species Buregia bispinosa Zaspelova in Polenova, 1953) in that the heteromorphs lack a posterior crumina-like antrum [as documented by Adamczak & Coen 1992, for B. ovata (Kummerow, 1953)] which is characteristic of the “Clavofabellina group” (Adamczak 2005b). Urftella? sp. (Figs 8A-O) Material. 13 poorly preserved carapaces including CPC 16804-16810. Description. Heteromorph: Lateral view outline elongate, slightly preplete; dorsal border straight, long, cardinal angles anterior greater than posterior, greatest height slightly in front of mid-length position. Dorsal view – outline suboval, tumid, greatest width slightly posterior to mid-length position. Ventral view – no velar ridge observed. Adventral structure in form of a marginal ridge. Posterior view – dorsum epicline, greatest width in ventral half of carapace, perimarginal ridge at posterior end (Fig. 8D, M). Surface finely reticulate. Internal structures unknown. Tecnomorph: as for heteromorph, except for lack of perimarginal ridge, and some variation in outline in dorsal and ventral views, due to position of greatest width. Dimensions. See Table 1. Remarks. The larger (1.30L) presumed adult heteromorph carapaces possess features suggesting the species probably belongs to Urftella Becker, 1970, viz., similar lateral and ventral outlines, a finely reticulate surface and a perimarginal ridge at the posterior end. However, the material is not sufficiently well preserved to be determined with confidence, and is tentatively assigned to Urftella? sp. An alternative but equally uncertain assignment would be to Buregia Zaspelova in Polenova, 1953. The smaller (0.77L) carapace (Fig. 8D,G) appears to be a pre-adult (A-2) stage. Other smaller (0.60L or less) carapaces (Fig. 8AC, E-F, H-I) appear, at first sight, to have features of the “Parapribylites group”of Adamczak (2005b), viz., strongly reduced velar structures; these are tentatively regarded as juveniles (A-3
Locality
Figure
Table 1. Dimensions of Urftella? sp. For abbreviations see p. 279.
stage) of Urftella? sp. Comparisons. Specimens questionably referred to Urftella from the middle Frasnian of Belgium (Becker 1971; Casier & Olempska 2008), are unlike the Australian species. Of the known species of Buregia, the Australian species is similar to Buregia krestovnikovi Polenova, 1953, from the Evlanovian (late Frasnian) of the East European Platform. However, in view of the imperfect preservation of the available material, its assignment is uncertain. Occurrence. Samples taken from auxiliary sections in the type section (105, Veevers & Roberts 1968) of the Buttons Formation with heights above base: 02/07 (87 m); 02/09 (93m); 03/07 (99m), 03/14(120m); 04/01A(120m); 05/10(124m); 05/15 (139m); 05/31 (187m). Suborder PLATYCOPINA Sars, 1866 Diagnosis. (Adamczak 2004b, p. 45) Contact line of valves in dorsal aspect straguloidal to secondarily straight; hinge bipartite (kloedenellids) to holosolenic (cavellinids and cytherellids); carapace surface variously sculptured to smooth; distinct dimorphic features developed; female carapaces provided with a brood pouch situated in posterior part of domicilium; brood chamber separated from the rest of the domicilium by a dorsoventral inner partition (kloedenellids, cavellinids) or delineated as two depressions (especially younger cytherellids). Remarks. The arguments advanced by Becker (1990) and Adamczak (1991) that the Suborder Platycopina has a closer affinity to the palaeocopes rather than the Podocopida are accepted here. The concept of the Platycopina (sensu lato) used here follows that of Adamczak (2004a, b). That is, his enlarged (“alternative”) version of the suborder that tentatively includes the superfamily Barychilinoidea (assumed to be a link between the palaeocopines and platycopines) with the superfamilies Kloedenelloidea and Cytherelloidea. The adductor muscle scar pattern is either multiserial with many small scars (cavellinid-type) or biserial with fewer,
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CPC 7090 t CPC 16814 h CPC16815 h
H
W
H/L
W/H Locality Figure
0.94* 0.68 0. 45 0.72 0.67 0.95 0.63 0. 45 0.66 0.72 1.20 0.78 0.58 0.65 0.74
100/4 9G,H 145/5 9I,J 145/5 9M,N
larger scars, sometimes with an additional row of smaller scars (cytherellid-type). Superfamily KLOEDENELLOIDEA Ulrich & Bassler, 1908 Diagnosis. (Adamczak 2004b, p. 45) Platycopina with right or left valve larger; hinge bipartite and separated anteriorly or posteriorly or both, from contact groove, stragular process distinct; brood chamber always separated by an inner partition (limen). Family KLOEDENELLIDAE Ulrich & Bassler, 1908 (nom. transl. Ulrich & Bassler, 1923; ex Kloedenellinae Ulrich & Bassler, 1908) Diagnosis. (Adamczak 2003a, p. 358; emend.) Platycopina with left valve larger; hinge bipartite and separated anteriorly or posteriorly or both from contact groove, stragular process distinct; brood chamber always separated by an inner partition (limen); AMS pattern primitive, random aggregate. Remarks. The Kloedenellidae sensu Adamczak (2003a) comprises two developmental trends (groups) based on valve overlap. One (L>R) group is based around Kloedenella Ulrich & Bassler, 1908 and the remaining (R>L) forms are grouped with Lichvinia Egorov, 1950. Adamczak (2003a) allowed for both groups to be treated as subfamilies, but it is important to be aware that the Lichviniinae sensu Adamczak (2003a, = “R>L: Group Lichvinia Egorov, 1950”) is a provisional and broader grouping of genera compared with those in the Lichviniidae sensu Abushik (1990). Although both concepts have many genera in common (e.g., Alveolella Abushik, 1971; Dizygopleurella Samoilova & Smirnova, 1962; Evlanella Egorov, 1950; Kalugia Egorov, 1950; Kamaroiella Samoilova & Smirnova, 1983; Lichvinellina Neckaja, 1973; Lichvinia Posner in Egorov, 1950), the Adamczak scheme also includes some genera (Eukloedenella Ulrich & Bassler, 1923; Ispharaella Abushik, 1968; Nyhamnella Adamczak, 1966) that Abushik (1990) refers to other families. Superfamily CYTHERELLOIDEA Sars, 1866 Diagnosis. (Adamczak 2004b, p. 45) Platycopina
Table 2. Dimensions of Cavellina sp.A Jones, 1968. For abbreviations see p. 279. * = estimate.
with right, holosolenic valve always larger; overlaps all around the smaller; brood chamber separated by the inner partition (Family Cavellinidae Egorov, 1950) or delineated by two depressions in each valve (Family Cytherellidae Sars, 1865). Family CAVELLINIDAE Egorov, 1950 Remarks. See Adamczak (2003b) for a recent evaluation of the genera belonging in this family. Cavellina Coryell, 1928 Type species. Cavellina pulchella Coryell, 1928, p. 89, pl. 11, fig. 5 (by origination designation); Middle Pennsylvanian (Desmoinesian) Holdenville Formation and Upper Pennsylvanian (Missourian) Seminole Formation, Oklahoma, USA. Diagnosis. (Adamczak 2003b, p. 379) Cavelliniidae with variably rounded lateral carapace outline; neither sulcate nor ornamental features developed. Cavellina sp. A Jones, 1968 (Fig. 9G-J, M-N) 1968 Cavellina sp. A; Jones, p. 53, pl. 6, figs 1a, b. 1974 Cavellina sp. A; Jones, p. 12. Description. (See original description; Jones 1968, p. 53). Dimensions. See Table 2. Remarks. The original figured specimen (CPC 7090) is a male dimorph with the greatest width in dorsal view slightly posterior to the mid-length position. Later material (Fig. 9I, J, M, N) included females with the greatest width considerably closer to the posterior end. Comparison. Cavellina sp. A bears some resemblance to C. sphenoidea Rome, 1977 from the lower Tournaisian (Tn1bα) of Belgium. According to Coen et al. (1988, p. 11) the Belgian specimen figured by Becker & Bless (in Becker et al. 1974, pl. 7, fig. 7) as Cavellina coela (Rome, 1974) [sic] belongs in C. sphenoidea
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Figure 9. A-F, Beyrichiopsis? anogma sp. nov. A, C, right valve (0.71L), Holotype CPC 7087, dorsal, lateral; B, D, carapace (0.65L) CPC 16811, dorsal, right lateral; E, F, carapace (0.55L) CPC 16812, dorsal, left lateral; G-J, M-N, Cavellina sp. A Jones, 1968; G-H, carapace (male, c. 0.94L) CPC 7090, left lateral, dorsal; I-J, carapace (female, O.95L) CPC 16814, left lateral, dorsal; M-N, carapace (female, 1.20L) CPC 16815, left lateral, dorsal; K-L, O-Q Sulcella altifrons Jones, 1968; K-L, carapace (male, 0.83L) CPC 16818, left lateral, dorsal; O, carapace (male?, 0.90L) CPC 16817, left lateral; P-Q carapace (female, 0.98L) CPC 16816, left lateral, dorsal.
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AAP Memoir 39 (2010) Rome, 1977. The Becker & Bless specimen is conspecific with Cavellina sp. 36 of Becker & Bless (1974, pl.13, figs 1-7), a species with a range from Fa2aα to Tn1a (Becker & Bless 1974, fig. 11), which consequently would also apply to C. sphenoidea. Occurrence. This species is extremely rare in the Buttons Formation. Only 8 specimens were found in the original study (Jones 1968), and these were all from the Eight Mile Creek sections at localities 100/4, 145/5 and 145/7. Those in the 1978 collection from locality 02/02 (72 m above the base of section 105) are the first to be found in the type section. Sulcella Coryell & Sample, 1932 Type species. Sulcella sulcata Coryell & Sample, 1932, p. 274 (by original designation); Middle Pennsylvanian (upper Desmoinesian), Lone Camp Group, East Mountain Formation, Mineral Wells, Palo Pinto County, Texas, USA. Diagnosis (After Adamczak 2003b, p. 386). Cavellinidae with subrectangular lateral carapace outline, posteroventral margin truncated (distinct stragulum); adductorial pit present or absent. Remarks. Adamczak (1968, p. 93) recognised two subgenera of the genus Sulcella: Sulcella (Sulcella) Coryell & Sample, 1932 – with a kloedenellid shape of carapace, and distinct adductorial pit, and Sulcella (Postsulcella) Adamczak, 1968 – with kloedenellid type of external carapace morphology, and adductorial pit subdued or absent. Polenova (1966, p. 22) pointed out that Uchtovia Egorov, 1950 (type species U. polenovae Egorov, 1950) is morphologically close to Sulcella, but she distinguished the former genus from the latter by the almost straight dorsal margin, the step-like ridge at the posterior end (i.e., posterior shoulder) of male carapaces, the contiguous valves along the posterior part of the dorsal margin, and the absence of a ridge and groove along the anterior end. Rozhdestvenskaya (1972, p. 41) challenged my suggestion (Jones 1968, p.54) that Uchtovia is a junior synonym of Sulcella. She pointed out (on the subject of Sulcella altifrons Jones, 1968) that the hinge margin in this species lies in a small depression in the posterior half of the dorsal margin, which as an accepted characteristic of Uchtovia, allowing S. altifrons to be referred to that genus. Rozhdestvenskaya (op. cit.) added that the LV is entirely overlapped by the RV in species of Sulcella (as it is in species of Cavellina), but there is no overlap between the valves at the posterior end in those
of Uchtovia. Coen (1985, p. 16), in his discussion of the genus Uchtovia, stated that although the posterior shoulder is not a clear marker in the type species, the feature is more or less clear in males and larvae, and is part of the original (generic) description. He noted (op. cit.) that with the hingeline a little oblique, gently incised behind the stragulum, Sulcella of Adamczak (1968) appears to be equally attributable to the genus Uchtovia (minus Postsulcella). Abushik (1990, p. 131) retained Uchtovia as a valid genus within the family Mennerellidae Polenova (in Chernysheva, 1960, p. 322). Adamczak (2003b, p. 388) later confirmed that he regarded Uchtovia Egorov, 1950 as a junior synonym of the subgenus Sulcella (Sulcella) Coryell & Sample, 1932. Recent studies (e.g., Evdokimova 2006) recognise species referred to both Sulcella (Postsulcella) and Uchtovia in the northwestern East European Platform of Russia. However, the relationship is complicated by the fact that Coen (1985, p. 16) regarded Sulcella (Postsulcella) testis Adamczak, 1968 [type species of the subgenus S. (Postsulcella)] as a junior synonym of Cavellina abundans Pokorný, 1951, which he in turn referred to Uchtovia. The ongoing debate concerning the relationship between Uchtovia and Sulcella may not be resolved without detailed knowledge of the internal morphology (i.e., contact margin, hinge structure and adductor muscle scar patterns) of the type species of both genera. Sulcella (Postsulcella) Adamczak, 1968 Type species. Sulcella (Postsulcella) testis Adamczak, 1968, p. 97 (by original designation); Middle Devonian (lower Eifelian), Grzegorzwice beds, Wydryszów, Poland. Remarks. See Adamczak (2003b, p. 388). Sulcella (Postsulcella) altifrons Jones, 1968 (Fig. 9K-L, O-Q) 1968 Sulcella altifrons; Jones, p. 54, pl. 4, figs 6-8, 1972 Uchtovia altifrons (Jones); Rozhdestvenskaya, p. 41, 1974 Uchtovia altifrons (Jones); Jones, p.11. 1985 Uchtovia altifrons (Jones); Coen, p. 16. Material. Figured CPC 16816 female; CPC 16817, CPC 16818; all from 04/01A Diagnosis. Sulcella (Postsulcella) with greatest height in anterior half, valves smooth, subdued adductorial pit; posterior ridge absent.
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L
CPC 16816 CPC 16817 CPC16818
0.98 0.90 0.83
H
W
H/L
W/H Figure
0.50 0.45 0.51 0.90 9P,Q 0.45 0.33 0.50 0.72 9O 0.43 0.30 0.52 0.70 9K,L
Description. See Jones (1968, p. 55). Dimensions. See Table 3. Remarks. Contrary to Rozhdestvenskaya’s (1972) referral of this species to Uchtovia Egorov, 1950, I prefer to retain it in Sulcella (Postsulcella), because it is non-sulcate, and the tecnomorphs lack the distinct posterior shoulder that Polenova (1966) regards as diagnostic of the males and larvae of Uchtovia. Comparisons. Sulcella (Postsulcella) altifrons was originally (Jones 1968, p. 56) compared to Cavellina abundans Pokorný, 1951 [= Sulcella (Postsulcella) or Uchtovia] but distinguished by its oblique hinge-line, gently incised behind the stragulum. Rozhdestvenskaya (1972, p. 41) distinguished her species Uchtovia famenica from Sulcella altifrons by its shorter and wider shell, almost the same curvature of ends, and the absence of overreach of RV along the dorsal border of LV, posterior to the stragulum. The Russian species also possesses a distinct adductorial pit/sulcus. Occurrence. This species is common in the lower and middle parts of the type section of the Buttons Formation from 18 m (105/60) to 208m (05/38) above the base. Found in intervening samples at 30m (105/100), 52m (105/170), 93m (02/09), 120m (04/01A), 128m (105/420), 129m (03/17), 131m (105/430), 112m (05/05), 145m (05/17) and 183m (105/600) above the base. Eight-Mile Creek localities of Buttons Formation at 100/4 and 606/9, and in DDH 13 drill hole north of Pincombe Range, at depths of 110-115m and 145-150m. Superfamily BARYCHILINOIDEA Ulrich, 1894 [Platycopina sensu lato; enlarged, “alternative” version of the suborder Platycopina: Adamczak 2004a] Diagnosis. (Adamczak 2004a, p. 129, modified) Assumed platycopines with mostly preplete (‘slightly postplete’, Adamczak) carapace outline, RL overlap. Axis of greatest length extends from anteroventral border to posterodorsal border, inclined at about 75° to the height. Distinct lip-like carinae on dorsal and ventral borders of both valves. Hingeline straight, depressed in deep channel between dorsal carinae and distinct stragular processes on RV (sansabelloid-type). Adductor muscle scar pattern primitive (random aggregate) situated slightly anterior of mid-length position. Surface ornamentation rows of anastomosing low ridges with intervening grooves containing rows of punctae (pore-canals?), oriented approximately parallel to axis of valve. Dimensions. See Table 6. Most of the 30 specimens measured for the size-dispersion diagram (Jones 1968, fig. 18) are between 0.60 and 1.00 mm in length. No dimorphs were found within this size range, as they are probably tecnomorphs (juveniles and possible males). However, dimorphism was recognised in slightly larger specimens of Diphyochilina abushikae Rozhdestvenskaya, 1972 (1.18L; 1.24L). Remarks. Adamczak (2006c, p.16, fig 5.3a) illustrated a topotype of D. tryphera which was stated to be a “right view”. This figure is actually a left lateral view, as it shows distinct RL, hinge deeply incised, hingement formed by groove in RV which receives the dorsal edge of the LV. Remarks. Jones (1968, p. 46) gave a translation of Polenova’s (1960) diagnosis. This genus is incompletely understood and requires further investigation. Some confusion exists as to the orientation of species belonging to this genus, depending on which valve (RV or LV) is the larger, which in turn, affects the direction of swing in lateral view (preplete or postplete). An example of this confusion is found in the author’s (Jones 1968) previous, now discarded, interpretation of the Buttons species as preplete (see below). Adamczak (2004a) considered Coelonellina as a probable barychilinid form, an opinion with which I concur, but in the Serenididae within the Barychilinoidea. The type species of Microcoelonella Coryell & Sohn, 1938 (M. scanta Coryell & Sohn, 1938) from the Mauch Chunk Series (Upper Mississippian) of West Virginia, is morphologically close to Coelonellina, but is amplete. Sohn (1971, p. A7) thought the holotype was probably a juvenile, and considered “both the species and genus as nomina dubia, until additional material is studied”, which is still the situation today. Coeloenellina sp. cf. C. fabiformis (Kesling & Kilgore, 1952) (Fig. 11O-Q) 1952 Schmidtella fabiformis; Kesling & Kilgore, p. 2-3, pl. 2, figs 1-7. 1968 Coeloenellina sp. cf. C. fabiformis (Kesling & Kilgore, 1952); Jones, p. 46, pl. 1, figs 12a-d. 1974 Coeloenellina sp. cf. C. fabiformis (Kesling & Kilgore, 1952); Jones, p. 12.
Table 7. Dimensions of Coeloenellina sp. cf. C. fabiformis Kesling & Kilgore, 1952. For abbreviations see p. 279.
Dimensions. See Table 7. Remarks. This species is similar to C. fabiformis from the Middle Devonian Genshaw Formation of Michigan (Jones 1968, p. 47). The lateral outline of the Buttons Formation specimens was interpreted as preplete (LV larger) based on a comparison with paraparchitoids, in which the end having the greatest height is anterior (Jones 1968). However, the orientation used by Polenova (1952, 1960) is retained here, i.e., the RV is the larger, permitting the lateral outline to be interpreted as postplete. The same orientation and postplete outline is adopted for the Buttons species. Comparisons. This species is close to C. optata (Polenova, 1955) from the late Givetian of the Ural Mountains (Polenova 1955) and of the Ardennes, Belgium (Coen 1985). The Australian specimens, however, have a narrower R>L posteroventral overlap. In lateral and dorsal outline, and incised dorsum, Paraparchites discus Williams et al., 2005 from the late Tournaisian of Scotland, resembles the Australian species. Although conspecificity is unlikely, such comparison suggests that the Scottish species is more likely to belong to Coeloenellina than to Paraparchites. Occurrence. Present in only one sample (05/47) of the Buttons Formation type section, 235 m above the base. Eight Mile Creek localities: 100/4 (=144/1), 145/5, /8, /9, 146/10 (CPC 16864), 146/13, 606/11, /20, and /22. Knox Creek Plain area WBS 4171 at depth of 58-62 m. DDH 13 drill hole north of Pincombe Range, at depths of 145-150 m and 170-175m. Suborder UNCERTAIN (“non-kloedenellaceans” sensu Adamczak (2004a; = Knoxitacea Egorov, 1950 sensu Olempska 1999)
Material. 36 complete carapaces. Description. Subovate, postplete outline. Inequivalved R>L overlap along ventral border. Hinge-line straight, long, about three-quarters length of carapace, depressed between slightly convex dorsal border of each valve. Posterior and ventral borders broadly rounded; anterior border obliquely truncated ventrally. Greatest height posterior of mid-length position. Hinge-structure unknown. Surface nonlobate, smooth.
Diagnosis. Ostracods with straight-backed subquadrate to subelliptical carapace outline. RV larger than LV. S2 a sulcus or pit. Hingement ridge and groove type. Adductor muscle scar pattern primitive (random aggregate). Dimorphism expressed as inflated posterior part of female valves but internally with no trace of limen. Remarks. The “non-kloedenellaceans” sensu Adamczak (2004a) are the residual taxa after Adamczak (1991) restricted the Kloedenellacea
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AAP Memoir 39 (2010) to those forms with kloedenellid dimorphism; i.e., female carapaces provided internally with a dorsoventral partition (limen) which separates the brood chamber from the remainder of the domicilium. This includes a group of families of kloedenellacean-like genera which lack a limen, viz., Geisinidae Sohn, 1961 (= Knoxitidae Egorov, 1950), Glyptopleuridae Girty, 1910 and Beyrichiopsidae Henningsmoen, 1953. Geisinidae possess a calcified internal rim (sensu Olempska 1999) which, if comparable to a duplicature, would indicate a podocopine relationship (Adamczak 2006a). The higher taxonomic position of the “non-kloedenellaceans” sensu Adamczak (2004a) is still to open to debate. Family GEISINIDAE Sohn, 1961 [= Knoxitidae Egorov, 1950] Diagnosis. (After Adamczak 2006a, p. 278) Presumed podocopine ostracods (superfamily unknown) being provided with weak and small duplicatures, (to a certain degree) showing common carapace characteristics: valves basically subrectangular in lateral aspect, distinctly sulcate, slightly aymmetrical, while showing right over left overlap (as a rule, most distinct along ventral margin); ridge and groove hingement developed, hinge typically bipartite, with conspicuous stragulum, posterior part channelled; lateral spines present; valve surface delicately reticulate; females showing inflated posterior part of carapace (lacking kloedenellid inner partition). Remarks. The genera included in this family are Geisina Johnson, 1936, Knoxites Egorov, 1950, Hypotetragona Morey, 1935 (=Knoxiella Egorov, 1950, Plavskella Samoilova, 1951), Carboprimitia Croneis & Funkhouser, 1939, Kloedenellina Coryell & Johnson, 1939, and possibly Marginia Polenova, 1952 (see below). Geisina Johnson, 1936 Type species. Beyrichiella gregaria Ulrich & Bassler, 1908 (Johnson 1936, p. 21, by original designation); Upper Pennsylvanian, Missouri Series, Kansas City, Missouri. Diagnosis. (Adapted from Adamczak 2006a, p. 284) Geisinidae (= Knoxitidae) with anterior (S1) sulcus shallow or missing; short and distinct adductorial (S2) sulcus, hinge sansabelloid, stragulum weak, hinge margin incised behind S2, between dorsal humps; posterodorsal spine or inflated bulb present. Remarks. Earlier concepts of this genus (Sohn
1961; Pollard 1966; Jones 1968) have been confirmed by several authors (e.g., Kaesler & Hecht 1992; Adamczak 2006a). Kaesler & Hecht (1992), who examined the syntypes and new material of Geisina gregaria, noted subtle sexual dimorphism in that “females are slightly less elongate than males and are more inflated posteriorly”. Abushik (1990, p. 132) also distinguished Geisina from Knoxites by its weakly developed S1 and the presence of a posterodorsal lobe or spine. Geisina monothele Jones, 1968 (Figs 12A-D) 1968 Geisina monothele; Jones, p. 26, pl. 3, figs 8-10. 1972 Geisina monothele Jones, 1968; Rozhdestvenskaya, p. 48. 1974 Geisina monothele Jones, 1968; Jones, p. 11-12. Material. More than 100 carapaces. Additional material studied includes CPC 16865 (locality 04/01A) and CPC 16866 (locality 105/450) Revised diagnosis. A reticulate species of Geisina with low nipple-like spine on L3 of LV. Description. See Jones (1968, p. 26-27; additional comments herein). The entire surface of Geisina monothele was originally described (Jones 1968, pl. 3, figs 8-9) as smooth, but the present SEM investigation shows that reticulations are present (Fig. 12B-D) and their apparent partial or complete absence in some specimens is due to poor preservation. In smaller (juvenile) specimens the posterodorsal border does not extend above the hingeline, and the spine on the L3 of the LV is more robust than in more mature specimens. A narrow, smooth rim originally described at the “free margin of the LV” is here interpreted as a selvage on the RV, and the “delicate narrow striated marginal structure” also on the RV is probably a selvage fringe (sensu SylvesterBradley 1941). This structure is preserved in the holotype of G. monothele (Jones 1968, pl. 3, fig. 8e). In many specimens, it is not preserved (e.g., Fig. 12C, in which the free margins of the valves are not in contact, and show a contact groove along the ventral part of the free margin of the RV). Dimensions. See Table 8. Remarks. The interpretation of a selvage and fringe in this species implies the presence of a calcified inner lamella.
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Figure 12. A-D, Geisina monothele Jones, 1968; A, right valve (c. 0.75L) CPC 16831, hinge line; B, D, carapace (0.50L, juvenile) CPC 16830, dorsal, left lateral; C, carapace (0.70L) CPC 16829, left lateral; E, F, Marginia reticulata Jones, 1968, carapace (1.18L, adult) Holotype CPC 7063, ventral, left lateral; G-L, Marginia venula Jones, 1968; G, I, carapace (1.17L, adult) Holotype CPC 7060, left lateral, dorsal; H, left valve (anteriorly incomplete, 0.75H) CPC 16837, left lateral; J-L, carapace (0.60L, juvenile) CPC 16838, dorsal, left lateral, and detail of posteroventral margin.
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CPC 16829 c CPC 16830 juv. CPC 16831 RV
L
H
0.70 0.50 0.75*
0.45 0.35 0.50
W
H/L
W/H
Locality
Figure
0.35 0.64 0.78 105/430 12C 0.25 0.70 0.71 04/01A 12B, D 0.38 0.66 0.76 105/420 12A
Comparisons. Geisina monothele is superficially comparable to species (G. fecunda, G. multa) described by Rozhdestvenskaya (1972, p. 47, 48) from the early Famennian of Bashkiria. It differs from G. fecunda in the length and breadth of the adductorial sulcus (S2), more inflated pre-adductorial (L2) lobe, single posterodorsal spine (on LV), and finer reticulations of surface ornamentation. Geisina monothele is closest to G. multa in the length and breadth of the adductorial sulcus (S2) but differs in that it has a slightly more elongated carapace, and the posterodorsal border has a slightly more pronounced hump on L3, with a low spine on the LV. Occurrence. Ranges throughout Buttons Formation type section from 3 m (105/10) to to 183 m (105/600) above the base. Found in intervening samples at 18m (105/60); 55m (105/180), 93m (105/305); 97m (105/320; 05/01); 105m (03/09); 107m (105/350); 112m (05/05); 113m (105/370); 121m (05/08); 122m (105/400); 124m (05/09); 126m (04/03); 128m (105/420); 131m (105/430); 145m (05/17); 148m (05/18). Eight Mile Creek localities 100/4 (= 144/1). DDH 13 drill hole north of Pincombe Range, at depths of 145-150 m and 175-180 m. Knoxites Egorov, 1950 Type species. Knoxites menneri Egorov, 1950, p. 84 (by original designation); Late Devonian (Frasnian) Voronezh beds, Voronezh Anticline, East European Platform, Russia. Diagnosis. (adapted from Adamczak 2006a, p. 290) Knoxitidae with deep S2, weak S1; three differently shaped lobes present; L1 and L2 elongate; posterior lobe (L3) bears coarse, flattened node or papilla; posteriorly located ventral lobe present. Remarks. Adamczak (2006a) noted that Knoxites displays a Knoxiella carapace morphology, but has a distinct post-adductorial lobe, and is assumed to be a member of the Geisinidae. In addition to the original diagnosis (Egorov 1950, p. 84) other diagnoses of the type species are given by Polenova (1953, p. 34) and Abushik (1990, p. 132). The calcified internal lamella illustrated by Gramm (1988, p. 22, pl. 15, fig. 12, pl. 27, figs 1-6) in Knoxites bolchovitinovae Egorov, 1950 is here interpreted as a calcified internal rim (sensu
Table 8. Dimensions of Geisina monothele Jones, 1968. For abbreviations see p. 279. * = estimate.
Olempska 1999). Knoxites perplexa (Jones, 1968) (Figs 11I, L-N) 1968 Beyrichiopsis? perplexa; Jones, p. 40, pl. 3, figs 1-5 (not figs 6-7 = Beyrichiopsis teicherti sp. nov.). 1974 Beyrichiopsis? perplexa Jones; Jones, p. 12. 1976 ?Knoxites perplexa (Jones, 1968); Lethiers, p. 246, pl. 1, figs 1, 2. Material. 16c (7h; 9t). Holotype h CPC 7065 (Fig. 11I, L) from locality 100/4, Eight Mile Creek, Buttons Formation. Paratype A, CPC 7066 (Fig. 11M, N). Paratype B, CPC 7067 (Jones 1968, pl. 3, figs 3a-c). Figured specimens in Jones 1968, CPC 7068 (op. cit. pl. 3, figs 4a, b), CPC 7069 (op. cit. pl. 3, figs 5). Revised diagnosis. Knoxites species with bulbous L3, lateral crest in the ventral region, marginal striated frill. Surface of carapace finely reticulate. Description. See Jones (1968, p. 40-41). The original figures (op. cit. pl. 3, figs 1-5) of the type specimens, photographed optically, demonstrate the presence of the lateral crest in the ventral region, more convincingly than the present SEM figures (Fig. 11I, M). Dimensions. See Table 9. Remarks. Lethiers (1976) described specimens from the early Famennian of the western Ardennes (northern France/Belgium) which he regarded as conspecific with Beyrichiopsis? perplexa Jones, 1968, and referred to the genus Knoxites. The present study leads me to agree with this generic assignment for most of the material of the Australian taxon (Jones 1968, pl. 3, figs 1-5), except for two figured specimens (op. cit, figs 6, 7), which are referred below to a new species of Beyrichiopsis. The new species is common in the type section (105) of the Buttons Formation along the Ord River, whereas Knoxites perplexa was based on specimens mostly collected from the type locality 100/4, and other Eight Mile Creek localities. Both taxa appear to be geographically mutually exclusive.
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CPC 7065 Holotype CPC 7066 Paratype A CPC 7067 Paratype B CPC 7068 CPC 7069
L
H
W
H/L
W/H Locality
0.76 0.76 0.74 0.66 0.60
0.45 0.47 0.45 0.40 0.37
0.39 0.32 0.34 0.30 0.27
0.59 0.62 0.61 0.61 0.62
0.87 0.68 0.76 0.75 0.73
Comparisons. Lethiers (1976) noted his specimens of Knoxites perplexa have often lost their microornamentation, and rarely show the reticulation and ventral ridge on the LV. The L3 is higher above the dorsal border than in the Australian individuals, otherwise all other characters agree. Although there is a superficial similarity, they are not sufficiently well preserved to be confidently referred to the Australian species. Gozalo (1994, p. 85-87, pl. 11, figs 12-14, pl. 12, figs 1-3) described the subspecies Knoxites perplexa vini from the early Famennian (lower part of the Filluelo Member of the Hoya Formation in the Tabuenca-Rodanas area, Zaragoza, northeastern Spain. His material differs from K. perplexa perplexa (Jones, 1968) in the lack of a ventral crest and a more subdued inflation of the L3 above the dorsal margin. He noted that the latter feature is nearer K. perplexa perplexa figured by Lethiers (1976). The sizedispersion ranges of both the Ardennes (Lethiers 1976, fig. 1) and Aragon (Gozalo 1994, fig. 37) material includes more juveniles than described for Knoxites perplexa (Jones, 1968). Occurrence. Buttons Formation, Eight Mile Creek localities 100/4 (= 144/1); 145/5; 146/10; 606/20, /22. This species is also present in the Canning Basin (CPC 16867); in the Clanmeyer Siltstone, Frome Rocks 2 (7100-7110 ft). Marginia Polenova, 1952 Type species. Marginia sculpta Polenova, 1952, p. 96 (by original designation); Middle Devonian late Givetian, Syzran, Samara Bend region, Russia. Diagnosis. (Adamczak 2006a, p. 296) Geisinidae? (or Beyrichiopsidae?) with short and narrow adductorial sulcus; small rounded presulcal lobe possible; valve typically bordered by radiate frill; 1-2 parallel ridges possible; valve surface reticulate to finely tuberculate. Remarks. The type species of Marginia is in need of further investigation (Adamczak 2006a). The genus appears close to Knoxiella Egorov, 1950 (= Hypotetragona Morey, 1935), which has a duplicature, and therefore can be treated as a geisinid (Adamczak 2006b, p. 296). Marginia
100/4 100/4 100/4 100/4 100/4
Figure
11I, L 11M, N unfig. unfig. unfig.
Table 9. Dimensions of Knoxites perplexa (Jones, 1968). For abbreviations see p. 279.
is occasionally referred to the Beyrichiopsidae (e.g., Abushik 1990, p. 136), and its close morphological likeness to Elenamarginia Berdan, 1986, especially Marginia sculpta multicostata Polenova, 1952 (an accepted beyrichiopsid) argues in favour of a beyrichiopsiid affinity. On the other hand, it is uncertain whether or not the radiate frill that borders the free margin of Marginia sculpta is homologous with the fimbriate or spinous admarginal structure of the type species of Beyrichiopsis. The problem of preservation and interpretation of marginal structures is exemplified by Marginia reticulata and M. venula Jones, 1968, discussed below. Marginia reticulata Jones, 1968 (Fig. 12E-F) 1968 Marginia reticulata Jones, p. 32, pl. 2, figs 4a-f, 5a-c. Revised diagnosis. Marginia with lateral surface ornamented by coarse polygonal reticulae of constant size, and surrounded by a smooth ridge along the border of each valve, parallel to free margin. Description. (see Jones 1968, p. 33; additional comments herein). The posterior, ventral, and anterior borders were originally described as smooth, but the present SEM investigation shows that the partial or complete absence of reticulations is due to poor preservation. Dimensions. 1.18L, 0.75H, 0.50W, 0.64H/L, 0.67W/H [Holotype (CPC 7063) locality 100/4]. Remarks. Rozhdestvenskaya (1972, p. 47) claimed this species lacks a rib-like fold on the ventral edge of each valve, which is characteristic of Marginia. She inferred that M. reticulata belongs to Geisina, by comparison with her species G. fecunda. Such a generic referral is clearly negated by the presence of a “narrow (admarginal) ridge parallel to the free margin of each valve” (Jones 1968, p. 33, pl. 2, figs 4a, e-f; Fig. 12E-F herein). However, it is uncertain whether or not this admarginal ridge represents a beyrichiopid marginal frill, which as pointed out by Adamczak (2006b, p. 448) is “generally speaking …. an ambivalent character. If weakly
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CPC 7060 CPC 16837 CPC 16838
H
W
H/L
W/H
Locality
1.17 0.75 0.49 0.64 0.65 100/4 --0.75 0.25 --- 0.33 03/17 0.60 0.40 0.30 0.67 0.75 146/10
Figures
12G, I * 12H 12J-L
Table 10. Dimensions of Marginia venula Jones, 1968. For abbreviations see p. 279. * = Holotype.
developed, the feature is often not preserved or was simply overlooked.”
marginal, radially striate frill, developed on both valves.
Occurrence. Buttons Formation Eight Mile Creek localities 100/4, 145/8, 146/10, 11, 13. Knox Creek Plain area WBS 4171 at depth of 58-62 m, 82-86 m. DDH 13 drill hole north of Pincombe Range, at depths of 81.6-85 m, 105-110 m. Also in Garimala Limestone (Ningbing Group) Veevers & Roberts (1968) localities 21/22 and 443/25.
Occurrence. Ranges throughout Buttons Formation type section from 18 m (105/60) to 183 m (105/600) above the base of the type section. Found in intervening samples at 52 m (105/170); 55m (105/180); 60m (01/20); 78m (02/04); 84m (02/06); 85m (105/280); 90m (02/08); 93m (02/09); 102m (03/09); 113m (105/370), 122m (105/400); 123m (04/02); 126m (04/03), 128m (105/420); 129m (04/04); 131m (105/430). Eight Mile Creek localities 100/4 (= 144/1), 145/5, 146/10, /11, 606/9, /11, /14, /19, /20, /22. DDH 13 drill hole north of Pincombe Range, at depth of 105-110 m.
Marginia venula Jones, 1968 (Fig. 12G-L) 1968 Marginia venula; Jones, p. 30, pl. 2, figs 1-3. 1974 Marginia venula Jones; Jones, p. 12. 1983 Marginia venula Jones; Lethiers, p. 45. 1986 Marginia venula Jones; Berdan, p.374. Revised diagnosis. Marginia with lateral surface ornamented by distinct vein-like costae, and surrounded by a smooth ridge along the border of each valve, parallel to free margin; this ridge extends anteriorly as far as L1; S1 well developed; dorsal border of L3 bears a crest. Description. (see Jones 1968, p. 31; additional comments herein). Remnants of a marginal frill on the RV only. Surface ornamentation consists of many coarse costae which tend to anastomose and bifurcate. Dimensions. See Table 10. Remarks. The holotype (CPC 7060) was lost during preparation for SEM; CPC 7061 is selected here as a neotype. A marginal ‘frill’ along the posteroventral margin of the RV was interpreted as a selvage seal (Jones 1968, p. 31), which therefore would imply the presence of a calcified inner lamella. However, if the structure is a remnant of a true beyrichiopsiid frill, a similar one has yet to be recognised on the smaller (LV) valve. Comparison. Marginia venula has a surface ornamentation like that of Elenamarginia Berdan, 1986 (type species E. polenovae Berdan, 1986; Early Devonian, Nevada), and to a lesser extent like that of Marginia lobanovoensis Polenova, 1955 (Middle Devonian Biya beds, Bashkiria). It is distinguished from Elenamarginia polenovae Berdan, 1986 by the lack of a distinct, thin
Family BEYRICHIOPSIIDAE Henningsmoen, 1953 nom. transl. Sohn 1961 (ex. Beyrichiopsiinae Henningsmoen, 1953) [synonymy as for Beyrichiopsiidae Sohn, 1961, in Adamczak 2006b, p. 448] Diagnosis. (Adamczak 2006b, p. 448-449) Palaeocopids (suborder and superfamily unknown) with valves basically sub-rectangular in lateral outline, unisulcate, slightly asymmetrical, RL along ventral margin. Hingeline straight, about 0.90L; posterior half slightly depressed in shallow channel, formed by posterodorsal border. Anterodorsal border with delicate ridge terminating at posterior cardinal area in a low tubercle. Stragulae not developed. Anterior cardinal angle 125°, posterior cardinal angle 90° or less. L1 absent. L2 prominent, extending below dorsal border. S2 narrow, deep, extending ventrally 0.45H. L3 subdued. Spinous admarginal ridge extends from anterior cardinal area posteriorly to the low tubercle in posterior cardinal area. Spines widely spaced at posterior end of RV. Adventral frill formed up to 15 strong spinous tubercles, extending from anteroventral
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CPC 16832 Paratype A CPC 16833 A?f Holotype CPC 16834 Paratype B CPC 16835 Paratype C CPC 16836 Paratype D CPC 7070 CPC 7071
L
H
W
0.88 0.79 0.73 0.68 0.68 0.75 0.72
0.50 0.45 0.43 0.38 0.38 0.43 0.44
0.31 0.34 0.30 0.28 0.25
H/L
0.57 0.57 0.59 0.56 0.56 -0.57 0.27 0.56
area to posteroventral area. Surface papillose. In dorsal view greatest width in mid-length position in tecnomorphs; in posterior half in heteromorphs. Dimensions. See Table 11. Remarks. The delicate ridge along the anterodorsal border is possibly an incipient dorsal fringe comparable with the more developed carina in Beyrichiopsis fimbriata Jones & Kirkby, 1886. Comparisons. Surface papillose, unlike the finely reticulate Knoxites perplexa. Occurrence. Buttons Formation at 52m (105/170), 84m (02/06), 97m (105/320), 113m (105/370), 120m (04/01A), 183m (105/600) and 189m (105/620) above base of type section. Beyrichiopsis? anogma sp. nov. (Figs 9A-F) 1968 Leptoprimitia sp. A; Jones, p. 42, 43, pl. 5, figs 5a, b, text-fig. 15. 1993 Lichvinella scopinensis Posner; Jones, p. 660. Derivation of name. Greek, an - without; ogmos - furrow; alluding to the weak adductorial sulcus (S2). Material. 4 specimens (1hRV; 3tc). Holotype. hRV CPC 7087 (Fig. 9A, C); previously illustrated by Jones (1968, fig. 5a, b, text-fig. 15) from locality 100/4, Buttons Formation, Eight Mile Creek, Burt Range area, Bonaparte Basin. Paratypes. tc CPC 16811 (Fig. 9B, D), and unfigured tc CPC 16813 from locality 105/10, Buttons Formation, type section (105 of Veevers & Roberts 1968), east bank of Ord River, 10 ft (3 m) above the base; tc CPC 16812 (Fig. 9E, F) from locality 02/09, Buttons Formation, type section 305 ft (93 m) above the base of section 105. Diagnosis. Beyrichiopsis? without well defined adductorial pit or sulcus. Continuous frill-like lateromarginal ridge. Surface reticulate.
W/H
Locality
02/06 04/01A 04/01A 04/01A 04/01A -105/170 0.62 105/600 0.62 0.76 0.71 0.60 0.66
Table 11. Dimensions of 11A, D Beyrichiopsis teicherti sp. nov. For abbreviations see p. 279. 11B, E 11C, F 11G, J 11H, K unfig. unfig. Figure
Description. Outline subquadrate-elongate in lateral view. Anterior end broadly rounded, merging imperceptibly into convex ventral border; posteroventral border obliquely truncated. Hinge-line straight, about 0.70L; stragulae not developed. Lateromarginal frill-like ridge completely surrounding lateral surface; dorsal part of ridge obscures hinge line. Adventral tubulate structure (remnants near anterodorsal corner) present. Bilobate with well developed posterior lobe in mature females; posterior area of lateral surface swollen, posteroventral area depressed. Sulcal depression faint or absent. Surface reticulate. In dorsal view greatest width at mid-length in males and juveniles; greatest width in posterior half in female. Dimensions. See Table 12. Remarks. This species was originally assigned to Leptoprimitia Kummerow, 1953, a genus now known to belong to the Metacopa (Zagora 1968, p. 51; Adamczak 1971, p. 127; 1976, p. 385-86). The species is excluded from that genus because, externally, dimorphism is expressed as an inflated posterior part of female valves, but internal structures (limen) are not known because single valves were not found. It is questionably referred to Beyrichiopsis because it lacks a well defined sulcus or pit, which is a typical feature of species referred to Leptoprimitia. Beyrichiopsis? anogma sp. nov. replaces the name for the taxon tentatively referred to Lichvinella scopinensis Posner, in an earlier abstract (Jones 1993, p. 660). Comparisons. In lateral view, Beyrichiopsis? anogma sp. nov. is superficially similar to several reticulate species that possess a continuous marginal ridge, but they also possess a distinct adductorial sulcus. These reticulate species include e.g., Glyptopleura sokolskyae Egorov (1950, p. 106, pl. 18, figs 12-31) from the Malevsk-Upinsk, lower Tournaisian, Moscow Basin; Beyrichiopsis glyptopleuroides Green (1963, p. 99, pl. 4, figs 2, 3, 5-11) from the lower Mississippian Banff Formation of Alberta, Canada; Lichvinella scopinensis Posner in Gurevich (1966, p. 37, pl. 1, fig. 1, not 2-5) from the Strunian Ozerk-
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CPC 7087 hRV Holotype CPC 16811 tc CPC 16812 tc CPC 16813 tc
L
H
W
H/L
W/H Locality Figure
0.71 0.65 0.55 0.63
0.40 0.35 0.33 0.35
0.17 0.22 0.15 0.20
0.56 0.54 0.59 0.56
0.85 100/4 9A, C 0.63 105/10 9B, D 0.46 02/09 9E, F 0.57 105/10 unfig.
Khovansk gorizont, Moscow Basin (also figured by Tschigova 1977, pl. 41, fig. 10, pl. 42, figs 4, 5); Glyptolichvinella? aff. chovanensis Posner sensu Gurevich (1966, p. 40, pl. 2, figs 3-5) from the Torchin suite of northeastern Volynia-Podolia); and Beyrichiopsis anulata Rome (1971, p. 14-16, figs 11-14) from the earliest Tournaisian, Tn1a of Feluy, Belgium. Some of the abovementioned species (Glyptolichvinella? aff. chovanensis Posner sensu Gurevich 1966, Beyrichiopsis anulata Rome, 1971 and Beyrichiopsis glyptopleuroides Green, 1963), which may be synonymous (Becker & Bless in Becker et al. 1974), have been tentatively referred by Tschigova & Alekseeva (1986) to their genus Glyptopleurella. This genus is discussed earlier in this paper under the Beyrichiopsidae, and is considered a nomen dubium. Beyrichiopsis? anogma sp. nov. is also similar to the LV figured by Sohn (1988, pl. 31.1, figs 20, 21) as Beyrichiopsis cf. B. carinata carinata Green, 1963 (late Kinderhookian, Alaska) in dorsal and lateral views, but the Australian species lacks the adductorial sulcus (S2). Sohn’s specimen appears to lack the characteristic marginal frill of Green’s species. Order PODOCOPIDA Müller, 1894 Suborder PODOCOPINA Sars, 1866 Remarks. Becker (2000a, p. 241) recognised two significant podocopine superfamilies in the Palaeozoic, the Bairdiocypridacea Shaver, 1961 and the Bairdiacea Sars, 1888. Both lack a contact groove in the outer lamella. Minor podocopine representatives in the Palaeozoic are the marine Bythocytheridae Sars, 1926 (Superfamily Cytheracea Baird, 1850), and the brackishfreshwater Darwinulidae Brady & Norman, 1889 (Superfamily Darwinulacea Brady & Norman, 1889). A fifth and remaining podocopine superfamily (Cypridacea Baird, 1845) which includes freshwater and marine families, has not been recorded in Palaeozoic rocks. Superfamily BAIRDIOCYPRIDOIDEA Shaver, 1961 [= Bairdiocypridacea Shaver, 1961; Becker 2000a] Remarks. The concept of the Bairdiocypridoidea followed here is that of Becker (2000a, p. 250-
Table 12. Dimensions of Beyrichiopsis? anogma sp. nov. For abbreviations see p. 279.
253) and includes the families Pachydomellidae Berdan & Sohn, 1961 and Bairdiocyprididae Shaver, 1961. Family BAIRDIOCYPRIDIDAE Shaver, 1961 Diagnosis. (Becker 2000b, p. 276) Bairdiocypridoidea with subtriangular carapace outlines; hinge-line straight or lightly arched, not significantly depressed; hinge tripartite or undivided; apical region high to low; bow-shaped projection mostly distinct, stop ridges in the larger valve at the place of largest overlap known in some species. Baschkirina Rozhdestvenskaya, 1959 Type species. Baschkirina memorabilis Rozhdestvenskaya (1959, p. 171, pl. 27, figs 1-3); by original designation; Middle Devonian (Eifelian) Biya beds, Tuymazy, western Bashkiria. Diagnosis. (Becker 2000b, p. 280) Bairdiocyprididae “with suboval to trapezoid, dorsally truncated lateral outline; hinge line depressed; smaller right valve with adventrally located posteroventral spine; anteriorly situated delicate spine or flange in smaller (sic) left valve possible. Lower Devonian – Lower Carboniferous; Russia, central and western Europe, China.” Remarks. The reference to the left valve as smaller in the above diagnosis is an obvious typographic error. Becker (2000b, p. 283) commented that Baschkirina (in contrast to the similar Krausella Ulrich, 1894) shows “... the posteroventral spine adventrally, i.e. set on the carapace surface at a distance from the free margin ...”. He pointed out (Becker 2001c, p. 406) that the posteroventral spine in Krausella is set admarginally. Becker (2000b, p. 283) also noted that in Baschkirina “the anterior protuberance (of the larger left valve) is, however, located marginally, i.e. immediately at the anterior free margin, which here seems to terminate in a delicate spine.” However, this feature is present in only a few species (e.g., B. rioponga Becker, 1992), and does not appear consistently in most species of Baschkirina. In the original diagnosis, Rozhdestvenskaya (1959, p. 170) noted an asymmetry of the convexity in
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CPC 7088* CPC 16842 CPC 16843
H
W
H/L
W/H
Locality Figure
0.92 0.50 0.45 0.54 0.90 105/350 13I, L 0.83 0.43 0.40 0.52 0.93 04/01A 13J, M 0.80 0.43 0.38 0.54 0.88 04/01A 13K, N
the two valves, located near the ventral margin in the LV, and near the dorsal margin in the RV. This asymmetry in end view is shown for the type species (loc. cit., pl. 27, fig. 1d), but is not observed in the Buttons Formation species. There are few species of Baschkirina that have been figured in end view, and such asymmetry in valve width may not be consistent for the genus. Baschkirina is similar to Acratia Delo, 1930, which has pointed ends in lateral view, but lacks a posteroventral spine. Becker (2001a, p. 291) noted that “Acratia species with a conspicuous, anteroventral beak were separated into the subgenus A. (Cooperuna) by Gründel (1962, p. 87), but are sometimes (in. litt.) treated as a distinct genus. Most Palaeozoic workers, however, don’t make use of such a structure. […] the development of the anteroventral part of the valve is very variable in the Acratia ‘group’, and is considered to be of minor taxonomic importance.” Rozhdestvenskaya (1972, p. 105) noted “undoubted similarities” between Baschkirina Rozhdestvenskaya, 1959 and the subgenus A. (Cooperuna) Gründel, 1962 and thought that phylogenetically, the latter is most likely to be a descendant of Baschkirina in the Late Devonian and Carboniferous. She (op. cit.) also regarded Acutiangulata Buschmina, 1968 (type species Carbonita acutiangulata Posner in Tschigova, 1960, p. 226) as a junior synonym of Acratia (Cooperuna) Gründel, 1962. This synonymy is not supported here for the following reasons: (i) in Acutiangulata both ends of the larger LV are symmetrical, rounded and close to the ventral margin, whereas in Acratia the anterior end is further from the ventral margin than the posterior end. (ii) in Acutiangulata only the ventral corners of the RV are pointed with possibly a rostral beak at the anterior end, whereas in Acratia both valves are pointed at both ends. (iii) the flattened part of the carapace in the type species of A. (Cooperuna) was said by Gründel (1962, p. 110) to extend along the entire ventral margin of both valves in ventral view, and was not confined to the beaked anterior end as suggested by Rozhdestvenskaya (1972, p. 105). This is unlike the type species of Acutiangulata, which has a rounded ventral margin in transverse section. Several Mississippian species from Russia and Western Europe form a closely defined group,
Table 13. Dimensions of Baschkirina dubitata (Jones, 1968). For abbreviations see p. 279. * = Holotype.
related to the type species of Acutiangulata. Furthermore, the genus has been recorded in the lower Carboniferous of the Bonaparte Basin, northwestern Australia (Jones 1975, 1989). Baschkirina dubitata (Jones, 1968) (Fig. 13IN) 1968 Krausella? dubitata; Jones, p. 49, 50, pl. 5, figs 6a-d, 7a-c. Material. More than 100 carapaces (including CPC 16842, 16843, 16869 and 16870) from locality 04/01A. Diagnosis. Baschkirina with small spine at posteroventral part of RV. Description. Carapace medium-sized, subtrapeziform in lateral outline. Dorsal border gently convex, greatest height about mid-length, sloping to posterior end with slightly steeper angle; anterodorsal border straight or gently curved, more than one-third of length of carapace; posterodorsal border broadly curved. Ventral border straight in centre, subparallel to dorsal border, gently curved towards ends. Anterior and posterior extremities located below mid-height. (Larger) LV distinctly overreaches (smaller) RV on anterodorsal and posterodorsal borders, with slight bow-shaped projection ventrally. Hingeline straight, slightly depressed. Carapace in dorsal view moderately biconvex, greatest width subcentral, slightly less than greatest height; in posterior view sides slope gently away from dorsum, greatest width at mid-height, well defined spine at posterior end of RV, situated adventrally. Carapace surface smooth. Dimensions. See Table 13. Remarks. This species shows very little variation, and is more appropriately referred to Becker’s revision of Baschkirina. Comparisons. This species appears to be morphologically closest to Baschkirina microspina Olempska (1979, p. 123, pl. 26, figs 1a- 2d), described from the late Famennian (Wocklumeria Stage, do VI) of the Holy Cross Mountains, Poland. The Polish species is slightly more elongate and wider than Baschkirina
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Figure 13. A, D, Cryptocyprios sp. cf. C. subgibberosa Buschmina, 1977, carapace (1.25L) CPC 16839, right lateral, dorsal; B, C, Bairdia (Rectobairdia) aff. philippovae Egorov, 1953, carapace (0.95L) CPC 16844, right lateral, dorsal; E-H, Bairdia (Bairdia) ordensis Jones, 1968; E, G, carapace (1.32L, adult) Holotype CPC 7094, right lateral, dorsal; F, H, carapace (1.32L, adult) Paratype CPC 7095, right lateral, dorsal; I-N, Baschkirina dubitata (Jones, 1968); I, L, carapace (0.92L) Holotype CPC 7088, dorsal, right lateral; J, M, carapace (0.83L) CPC 16842, dorsal, right lateral; K, N, carapace (0.80L) CPC 16843 right lateral, dorsal.
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CPC 16839 CPC 16840 CPC 16841
H
W
H/L
W/L
1.25 0.85 0.56 0.68 0.45 1.60 1.00 0.68 0.63 0.43 1.65 1.13 0.60 0.68 0.36
Locality
Figure
03/17 05/32 01/20
13A, D unfig. unfig.*
dubitata, but despite this, they may be conspecific. Baschkirina dubitata is quite dissimilar to the only other species of the genus previously found in Australia, Baschkirina? sp. of Jones (in Turner et al. 1981) described from the Cravens Peak beds (Early Devonian) of the Georgina Basin, western Queensland. Occurrence. Buttons Formation at 45m (01/15), 52m (105/170), 93m (02/09), 107m (105/350), 113m (105/370), 120m (04/01A), 124m (05/09), 154m (05/20), 201m (105/660), 208m (05/38) and 262m (105/860) above base of type section. EightMile Creek localities 100/4 (=144/1), 146/10, 606/11, 606/19. Knox Creek Plain area WBS 4171 at depth of 70-74 m. DDH 13 drill hole north of Pincombe Range, at depth of 150-155 m. Cryptocyprois Gorak, 1966 Type species. Cryptocyprois venusta Gorak, 1966, p.97, pl. 14, fig. 10 (by original designation); Novotroitsky Horizon (C1ta) (~Zavolzhsky Horizon, Russian Platform) Late Devonian, Donetz Basin, Ukraine, also Rudnyi Altai; Buschmina et al. (1981, p. 62, pl. 8, figs 1-2) Other species. There are at least 9 other species and subspecies, viz.: C. gibberosa Gorak, 1966 (p. 97, pl. 14, figs 11, 12), Styla (C1ta2), Late Devonian, Donetz Basin, Ukraine. C. magna Wang, 1988, M. praesulcata Zone of Nanbiancum section, Guilin, South China. C. subgibberosa Buschmina, 1977, lower Kassin Formation, Karaganda Basin, Kazakhstan. C. suborientalis obliqua Buschmina in Buschmina et al., 1981, Rudnyi Altai. C. suborientalis suborientalis (Buschmina, 1970b), Eltsov Synclinorium. C. suborientalis recta Buschmina in Buschmina et al., 1981, Rudnyi Altai. C. subsymmetrica subsymmetrica Buschmina, 1970b. C. subsymmetrica concinna Buschmina in Buschmina et al., 1981, Rudnyi Altai. C. cf. venusta of Wang, 1988, M. praesulcata Zone of Nanbiancum section. Remarks. Stepanaitys & Abushik (1990, p. 159) accepted Cryptocyprois as a valid genus, which they distinguished from Bairdiocypris by its
Table 14. Dimensions of Cryptocyprois sp. cf. C. subgibberosa Buschmina, 1977. For abbreviations see p. 279. * = crushed laterally.
higher, more rounded anterior end and lower, depressed posterior end. Becker (2000a, p. 245), on the other hand, excluded Cryptocyprois from the Bairdiocypridoidea. Cryptocyprois has not been studied to the same degree as Bairdiocypris, and details of its internal morphology (e.g., stop ridges) are unknown. However, despite the apparent similarity of these genera in lateral and dorsal outline, there are some subtle differences (Stepanaitys & Abushik op. cit.). Additionally, the ventral overlap (bow-shaped projection) tends to be behind or at mid-length position in Cryptocyprois, whereas it appears in front of midlength position in Bairdiocypris. Cryptocyprois sp. cf. C. subgibberosa Buschmina, 1977 (Figs 13A, D) cf. 1977b Cryptocyprois subgibberosa; Buschmina, p. 115-116, pl. 26, figs 1-3. Material. 6 specimens. Description. Carapace subtriangular in lateral view. Dorsal margin highly arched in LV (apical index large, 11.9), with greatest convexity at centre; anterodorsal margin gently arched, moderately steep; posterodorsal margin slightly convex, steeper than anterodorsal margin. Dorsal margin arched in RV, gently arched or nearly straight in mid-dorsal margin. Ventral margin sinuous, concave in mid-ventral region. Anterior end broadly rounded with extremity below mid-height; posterior end narrow, with greatest convexity near ventral margin. Greatest height at mid-length of carapace. Greatest length below mid-height. In dorsal view sides relatively convex, slight compression at posterior end of RV, greatest width at mid-length, below mid-height position. LV
