INTRODUCTION. During the last 140 years many papers on early planktonic foram- inifers from the Triassic and the Jurassic have been published. In all but one ...
Early Jurassic planktonic foraminifera from Hungary Agnes Gorog
Palaeontological Department of Eotvos University, Budapest, H-I083 Budapest, Ludovika terl ABSTRACT: Well-preserved specimens of Globuligerina geczyi n. sp. were separated using concentrated acetic acid from indurated "ammonitico rosso" limestone of Gerecse Mountains, Transdanubian Central Range, Hungary. This planktonic foraminifera, of Late Hettangian or Early Sinemurian age is one of the earliest recorded.
INTRODUCTION During the last 140 years many papers on early planktonic foraminifers from the Triassic and the Jurassic have been published. In all but one case (Globigerina bathoniana Pazdrowa 1969), the original descriptions of these species were based on studies with use of light microscope and often the specimens were in thin-sections or appeared as internal molds. These circumstances prevented the determination of the wall-structure, the surface ornamentation, porosity, and in many cases, even the apertural morphology. Xs these features are essential for the identification of planktonic foraminifers, a reexamination of these species using the electron microscope is required to determine whether these forms are indeed planktonic. Only a few of the Middle and Upper Jurassic species were refigured and revised using electron microscopy by Masters (1977), GrigeHs and Gorbatchik (1980), Stam (1986) and Riegraf (1987). A review of early planktonic foraminifers from the Middle and Upper Jurassic is given by Morozova and Moskalenko (1961), Fuchs (1973, 1975), Grigelis (1974), Masters (1977), Grigelis and Gorbatchik (1980), Gorbachik and Kuznetsova (1983), Stam (1986), Riegraf (1987), and Loeblich and Tappan (1988). These authors have different opinion on the systematics and validity of the species, but most of them agree in dividing these forms on the basis of test-shape (ratio of height/diameter) into two groups, lowand high-spired. Some authors (i.e. Grigelis and Gorbatchik (1980) and Loeblich and Tappan (1988)) classify the low-spired forms as Globuligerina genus and the high-spired forms as Conoglobigerina genus. Stam (1986) and Riegraf (1987) accept only one genus and three species to be valid, Globuligerina oxfordiana (Grigelis 1958) from the Middle Bajocian and Globuligerina bathoniana (Pazdrowa) and Globuligerina balakmatovae (Mozorova in Mozorova and Moskalenko 1961) from the Late Bajocian. In this paper a detailed study of well-preserved Lower Jurassic (probably Hettangian) planktonic foraminifera is presented which, to my knowledge, is the oldest species examined by the scanning electron microscope. The specimens occur in hard "ammonitico rosso" limestone, and were separated by a special method described below. Earlier, owing to the lack of a proper preparation method, the microfauna of this characteristic Jurassic facies could have been studied only in thin-sections and from marly intercalations, if the latter were present.
The oldest species described in the literature as planktonic are from the Upper Triassic of the Austrian Alps (Oberhauser 1960; KristanToUmann 1964; Fuchs 1968, 1969). However their systematic positions are doubtful, Fuchs (1975), Grigelis and Gorbatchik (1980) and Stam (1986) considered them to be benthic foraminifers. Four species were described as planktonic from the Lower Jurassic. From the Sinemurian of Lower Austria we know Oberhauserella crassa Fuchs 1970, Oberhauserella planiconvexa Fuchs 1970 and Schlagerina orbis Fuchs 1970 and from the Upper Pliensbachian of Eastern France Globigerina Hasina Terquem et Berthelin 1875. In addition, four species were illustrated from thin-sections: "Globigerina " sp. Schick (1903), from the lowermost Lower Jurassic of Southwest Germany, (re-examining the type-locality, however Riegraf (1987) did not find any planktonic foraminifera); "Globigerinidi" in Tamajo (1960) from Sicily; "Globigerina-like" forms in Geczy (1961), from "ammonitico rosso" limestone of Bakony Mountains, Transdanubian Central Range, Hungary; "Protoglobigerinids" in Wemli (1988), from "ammonitico rosso" limestone of Domuz Dag, Western-Taurus, Turkey. All of these species are not adequately described and illustrated. Therefore, well-documented planktonic foraminifera from the Lower Jurassic are not known at present (Masters 1977; Stam 1986, Riegraf 1987, Loeblich and Tappan 1988). MATERIALS AND METHODS The studied specimens were collected from the outcrop situated on the eastern side of Nagypisznice Hill, near Labatlan, Gerecse Mountains, Transdanubian Central Range (text-fig. 1). The foraminifers were recovered from the lowermost beds of the Pisznice Limestone Formation, disconformable overlying the Triassic Dachstein Limestone Formation. The Pisznice Formation is light red, flesh-coloured "ammonitico rosso" limestone (wackestone and mudstone). Foraminifers and intraclasts are common in the lower layers. Although the formation contains brachiopods and small ammonites, well-preserved, determinable ammonites have not been found yet. These beds correspond to the Upper Hettangian "Psiloceras megastoma horizon" (Vigh, Gy. 1925, 1940; Vigh, G. 1961; Konda 1985) on the basis of lithological analogy. The Pisznice Formation is overlain by the Tuzkovesarok Limestone Formation, which is
micropaleontology, vol. 40, no. 3, pp. 255-260, plate 1, text-figures 1-2, 1994
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Agnes Gorog: Early Jurassic planktonic foraminifera from Hungary (Terquem 1870), Astacolus scalptus (Franke 1936), Astacolus spirolina (Bornemann 1854) and Ichtyolaria cf. nympha (Kopik 1969). The benthic assemblage is of Early Jurassic age. Planktonic foraminifers were found in two samples; two in one sample, five in the other one. Weakly and strongly ornamented specimens were found together SYSTEMATIC DESCRIPTION Superfamily GLOBIGERINACEA Carpenter, Parker and Jones 1962 Family GLOBIGERINIDAE Loeblich and Tappan 1984 Genus GLOBULIGERINA Bignot and Guyader 1971 Globuligerina geczyi Gorog n. sp. Plate 1, figures 1 -9 Origin of name: After professor Barnabas Geczy, who first mentioned planktonic foraminifera from Pliensbachian "ammonitico rosso" limestone, in Bakonycsernye, Bakony Mountains, Transdanubian Central Range, Hungary. Type-locality and stratum: Eastern side of Nagypisznice Hill, Gerecse Mountains, Transdanubian Central Range, Hungary. Lower part of the Pisznice Limestone Formation, "ammonitico rosso" limestone, Upper Hettangian or Lower Sinemurian.
TEXT-FIGURE 1 Scetch map of the type-locality of Globuligerina geczyi n. sp., Nagypisznice Hill, Gerecse Mountains, Transdanubian Central Range, Hungary.
exposed in a large quarry on the south-western side of Nagypisznice Hill (text-fig. 2). Here, in the lower part of this formation, the occurrence of Arietites cf. hungaricus Hauer indicates that these beds correspond to the Lower Sinemurian "Coroniceras rotiformis horizon" (Vigh, Gy. 1925, 1940; Vigh, G. 1961). Four samples, about half a kilogramme each, were collected from indurated "ammonitico rosso" limestone. It was impossible to free the microfossils by standard processing methods. Accordingly, the rocks were dissolved in concentrated acetic acid in a similar way as described by Lethiers and Crasquin-Soleau (1988). The residue of the four samples contained about 220 well-preserved specimens of foraminifers. Most of them are benthic and only 7 (about 3%) are planktonic forms. The benthic foraminifera assemblage is characterized by Dentalina, Nodosaria, Pseudonodosaria, and Marginulina (about 50% of the total assemblage), and the Lenticulina group (18%). The following species could be determined: Involutina liassica (Jones 1853), Berthelinella kuhni Franke 1936, Marginulina hamus Terquem 1866, Trocholina granosa Frentzen \94l, Nodosaria fontinensis Terquem \S61, Nodosaria nitida Terquem 1858, Pseudonodosaria multicostata (Bornemann 1854), Dentalina exilis d'Orbigny 1849, Dentalina terquemi d'Orbigny 1849, Dentalina vetusta d'Orbigny 1850, Lingulina tenera Bornemann 1854, Lingulina testudinaria Franke 1936, Eoguttulina liassica (Strickland, 1846), Frondicularia spatula 256
Material: 1 well-preserved specimens are deposited in the Micropalaeontological Collection of the Hungarian Natural History Museum, Budapest, catalog nos. M.93.50.— M.93.56., together with benthic foraminifers from this layer Types: Holotype no. M.93.51., Plate 1, figures 1, 4; Paratypes no. M.93.50., M.93.52, M.93.53., M.93.54., M.93.55., and M.93.56., Plate 1, figures 2-3, 5-9. Diagnosis: Test low trochoid, consisting 2 whorls, with 7-8 spheroidal chambers, aperture large, semicircular, umbilical with a lip, sculpture of the test surface varies from tubercular to reticulate. Description: Test small, chambers coiled in low, regular or irregular-trochospire, with an H/D-ratio from 0.6 to 0.78; consists of 2 whoris, with spheroidal chambers; the first whori consists of 4 small chambers, arranged nearly planispirally; the last whorl consists of 3-4 chambers, considerably larger than the preceding and rapidly increasing in size; sometimes a large, younger chamber partly surrounds an older, smaller one (PI. 1, figs. 3, 7); periphery rounded; peripheral outline lobulate; sutures distinct and depressed; umbilicus small and shallow; aperture large, semicircular, umbilical, bordering by an imperforate, narrow lip, except on the umbilical margin; the apertures of the older chambers maintain their shape, lip, and position forming a foramen between the chambers (pi. 1. fig. 7); wall calcareous, radial, bilamellar (pi. 1, fig. 8), thin (about 10|Lim) and perforated; surface covered by tubercles or cells; tubercles range from fine and rounded (pi. 1, fig. 5-6, 9) to distinct and elongated (pi. 1, fig. 7-8); length of the tubercles is l-10|lm, the diameter l-2|im; cells deep, nearly quadrangular (pi. 1, fig. 1-4); size of the cells is 5-13|j.m; pores small, l-2^im in diameter, perpendicular to the surface of the wall and located at random; the density of pores is independent of sculpture of the test surface; the majority of pores are located between tubercles and inside the cells, usually only one pore in each cell, less frequently smaller pores (about 0.5|a,m in diameter) are also on the ridges that form cells (pi. l,fig. 4).
Micropaleontology, vol. 40, no. 3, 1994 Dimensions: in |im. Max. diameter, D: Heigth, H: H/D ratio:
Holotype 229 158 0.69
Smallest specimen 200 131
0.65
Largest specimen 305 200 0.66
Lokut Radiolarile Formation Bajocian f T o l g y h a t Limestone
Variability: The test-shape is low spired, ratio of H/D varies from 0.6 to 0.78. Sculpture of the chambers surface ranges from isolated tubercules to a network of ridges.
Aalenian
Remarks: This species is difficult to compare with other previously described Lower Jurassic species, since their descriptions and illustrations are not adequate (see "Introduction"). As recently the taxonomoic division of the early planktonic foraminifera is not uniform I found it better to keep the original genus name in several cases.
Toarcian _N
Similar problem arises in connection with several Middle and Upper Jurassic species of the high-spired group: Globigerina (Conoglobigerina) gaurdakensis Balakmatova and Morozova, in Mozorova and Moskalenko 1961, Globigerina (Conoglobigerina) avarica Morozova, in Mozorova and Moskalenko 1961 and Globigerina conica lovceva and Trifonova 1961, and in the low-spired group: Globigerina helvetojurassica Haeusler 1881, G. cf. helvetojurassica Haeusler in E. Seibold and I. Seibold 1960 and Globigerina terquemi lovceva and Trifonova 1961. Stam (1986) dealt with these species in detail, considering the high-spired forms as synonyms of Globuligerina bathoniana (Pazdrowa), the low spired forms as synonyms of G.oxfordiana (Grigelis) and a few as indeterminable species. The most similar Middle Jurassic species is Globuligerina oxfordiana (Grigelis) (in Bignot and Guyader 1966), however it differs from G. geczyi n. sp. in its denser and smaller (0.4-0.5p.m) pores, in its test surface being usually smooth or hispid, and in often having an ultimate chamber smooth or less ornamented than the previous ones. According to Grigelis and Gorbatchik (1980), on the surface of the Late Jurassic specimens the "tubercles partly or completely confluent, forming irregular and more or less quadrangular cells" similar to Globuligerina stellapolaris Grigelis 1977 from the Kimmeridgian and Volganian. The latter species is very similar to G. oxfordiana in shape of the test and arrangement and size of the pores. Stam (1986) considers these species as synonyms. The low-spired Globigerina spuriensis Bars and Ohm 1968 differs in its small, peripheral aperture. This aperture is not characteristic of the planktonic forms. Globuligerina balakmatovae (Morozova, in Morozova and Moskalenko) is distinguished from G. geczyi n. sp. by its slightly flattened chambers and by the occasional appearance of an imperforate equatorial band or a weakly developed keel (Stam 1986).
Formation
Kisgerecse Marl Formation
L
Pliensbachian Tuzkoves-arok Limestone Formation Sinemurian
-3m -0
Pisznice L i m e s t o n e a. F o r m a t i o n
Hettangian? I l l
TRIASSIC
Dachstein L i m e s t o n e Formation
\e brownish-red nodular limestone -""-'-'J red marl red limestone I ' l l light red limestone greyish-white, thick bedded limestone
Globigerina bathoniana Pazdrowa, and Globigerina (Conoglobigerina) dagestanica Morozova, in Mozorova and Moskalenko 1961 differ from G. geczyi n. sp. in their higher spire and their weakly sculptured test surface, which never shows deep cells, and the ultimate chamber is often less ornamented, than the previous ones.
TEXT-FIGURE 2 Stratigraphic column of Nagypisznice Hill, Gerecse Mountains, Transdanubian Central Range, Hungary (after Konda, 1985), showing the type strata of
ACKNOWLEDGMENTS Sincere thanks are due to my colleague Istvan Szente for his help in the preparation of the material. All scanning electron microscopy photographs were taken by Gizella Argyelan. This work was
supported by the OTKA Foundation (contract number: F4351) and by the Magyar Hitel Bank "Magyar Tudomanyert" Foundation.
Globuligerina geczyi n. sp.
257
Agnes Gorog: Early Jurassic planktonic foraminifera from Hungary REFERENCES BARS, H. and OHM, U., 1968. Der Dogger des Profils Roccetta, Prov. Trient, Italien, Globigerina spuriensis n. sp. Neues Jahrbuch fiir Geologie und Palaontologie Monatshefte 10:577-590. BIGNOT, G. and GUYADER J., 1966. Decouverte de Foraminiferes planctoniques dans I'Oxfordien du Havre (Seine-Maritime). Revue de Micropaleontologie, 9(2): 104-110. FUCHS, W., 1969. Zur Kenntnis des Schalenbaues der zu den Trias-"Globigerinen" zahlenden Foraminiferengattung Praegubkinella. Verhandlungen der Geologischen Bundesanstalt, Wien, 1969(2): 158-165. , 1970. Eine alpine, tiefliassische Foraminiferenfauna von Hemstein in Niederosterreich. Verhandlungen der Geologischen Bundensanstalt, Wien, pp. 66-145. , 1973. Ein Beitrag zur kenntnis der Jura-"Globigerinen" und verwandter Formen an Hand polnischen Materials des Callovien und Oxfordien. Verhandlungen der Geologischen Bundesanstalt, Wien, 1973(3):445-489. , 1975. Zur Stammesgeschichte der Planktonforaminiferen und verwandter Formen im Mesozoikum. Jahrbuch der Geologischen Bundesanstalt, Wien, 118:193-246. GECZY, B., 1961. Die Jurassische Schichtreihe des Tuzkoves-Grabens von Bakonycsernye. Annales Instituti Geologici Fublici Hungarici, XL!X(2):507-545. GORBACHIK, T N. and KUZNETSOVA, K. I., 1983. Jurassic and Early Cretaceous planktonic foraminifera (Favusellidae). Stratigraphy and paleobiogeography. Zitteliana, 10:459-466. GRIGELIS, A., 1974. Jurassic stage of planktonic foraminifera development. Doklady Akademii Nauk, SSSR, seria, Geologia, 219(5): 1203-1205. GRIGELIS, A. and GORBATCHIK, A., 1980. Morphology and taxonomy of Jurassic and Cretaceous representatives of the superfamily Globigerinacea (Favusellidae). Journal of Foraminiferal Research, 10(3): 180190.
lOVCEVA, R and TRIFONOVA, E., 1961. Tithonian Globigerina from North-West Bulgaria. Travaux sur la Geologie de Bulgarie, serie Paleontologie, 3:343-347. KONDA, J., 1985. Geological Key Sections of Hungary: Gerecse, Labatlan, Nagypisznice Quarry. Hungarian Geological Institut, Budapest. KRISTAN-TOLLMANN, E., 1964. Die Foraminiferen aus den rhiitischen Zlambachmergeln der Fischerwiese bei Aussee, Salzkammergut. Jahrbuch der Geologischen Bundesanstalt, Wien, 10:182 LOEBLICH, A. R., JR. and TAPPAN, H., 1988. Foraminiferal Genera and their Classification. - Plate. New York, 970+212. LETHIERS, F. and CRASQUIN-SOLEAU, S., 1988. Comment extraire les microfossiles a tests calcitiques des roches calcaires dures. Revue de Micropaleontologie 31(1 ):56-61. MASTERS, B. A., 1977. Mesozoic Planktonic Foraminifera. A world-wide review and analysis, in: RAMSAY, A. T. S.(ed.), Oceanic Micropaleontology, Academic Press, London, 1:301-731. MOROZOVA, VG. and MOSKALENKO, T A., 1961. Planktonic foraminifera of boundary deposits of the Bajocian and Bathonian stages of Central Dagestan (North-Eastem Caucasus). Voprosy Mikropaleontologii, 5:330, (Russain). OBERHAUSER, V. R., 1960. Foraminiferen und Mikrofossilien "incertae sedis" der ladinischen und kamischen Stufe der Trias aus den Ostalpen und aus Persien. Jahrbuch der Geologische Bundesanstalt, Wien 5:5-46. OESTERLE, H., 1968. Foraminiferen der Typlokalitat der BirmenstorferSchicten, unterer Malm (Teilrevision der Arbeiten von J. KUBLER et H. ZWINGLI 1866-1870 und von R. HAEUSLER 1881-1893). Eclogae geologicae Helvetiae, 61(2):595-792. PAZDROWA, O., 1969. Bathonian Globigerina of Poland. Annales de la Societe Geologique de Pologne, 39(l-3):41-56.
Plate Globuligerina gee: i Gorog n. sp.
258
1
Lateral side of holotype, no. M.93.51. The surface of the test is covered by a network of ridges. The arrow shows the semicircular aperture, x270.
2
Spiral side of paratype, no. M.93.53. The surface of the test is covered by a network of ridges, xl 80.
3
6
Umbilical side of paratype no. M.93.50. The surface of the test is covered by tubercles, x240.
7
Lateral side of paratype, no. M.93.55. The surface of the test is covered by a network of ridges. The partly surrounded older chamber can be seen on the left side. The arrow shows the semicircular aperture, x200.
Lateral side of paratype, no. M.93.56. The surface of the test is covered by elongate tubercles and short costellae. Broken chambers reveals the previous aperture (white arrow) and overgrown pores. A partly surrounded older chamber can be seen on the left side, x290.
8
4
Enlarged surface section of holotype, no. M.93.51., (fig. 1), showing the cells on the surface and pores, xl400.
Enlarged surface section of paratype, no. M.93.56., (fig. 7), showing the large semicircular aperture and the bilamellar wall structure (white arrow), x500.
9
5
Enlarged surface section of paratype, no. M.93.50., (fig. 6), showing the tuberculate surface and pores, xl500.
Spiral side of paratype, no. M.93.52. The surface of the test is covered by tubercles, x280.
Agnes Gorog
Plate 1
Agnes Gorog: Early Jurassic planktonic foraminifera from Hungary RIEGRAF, W., 1987. Planctonic foraminifera (Globuligerinidae) from the Callovian (Middle Jurassic) of Southwest Germany. Journal of Foraminiferal Research, 17(3): 190-211. SEIBOLD, E. and SEIBOLD, I., 1960. Foraminiferen der Bank- und Schwamm-Fazies im untem Malm Siiddeutschlands. Neues Jahrbuch fiir Geologie und Palaontologie Abhandlungen, 109:309-438. SCHICK, T., 1903. Beitrage zur Kenntnis der Mikrofauna des schwabischen Lias. Jahreshefte des Vereins fiir Vaterlandische Naturkunde in Wiirttemberg, 59:111-177. STAM, B. 1986. Quantitative analysis of the Middle and Late Jurassic foraminifera from Portugal and its implications for the Grand Banks of Newfoundland. Utrecht Micropaleontological Bulletins, 34:1-167.
Ammonites margaritatus. Memoires de la Societe Geologique de France, 2(3): 1-126. VIGH, Gy., 1925. Foldtani jegyzetek a Gerecse-hegysegbol. Geologische Notizen a. d. Gerecsegebirge. Jahresberichte der Kgl. Ung. Geologischen Anstalt uber die Jahre, 1920-23:60-68 (Hungarian). , 1940. Stratigraphische und Tektonische Beobanctungen in der Umgebung des Berges Nagypisznice. Jahresberichte der Koniglich Ungarischen Geologischen Anstalt Uber die Jahre 1933-1935, IV:14551478. VIGH, G., 1961. Esquisse geologique de la partie occidentale de la Montage Gerecse. Annales Instituti Geologici Publici Hungarici, XLIX(2):569589.
TAMAJO, E., 1960. Microfacies mesozoiche della Montagna della Busambra. Rivista di Mineralogia Siciliana, 11:130-151.
WERNLI, R., 1988. Les protoglobigerines (foraminiferes) du Toarcien at de I'Aalenien du Domuz Dag (Taurus Occidental, Turquie). Eclogae geologicae Helvetiae, 81(3):661-668.
TERQUEM, M. O. and BERTHELIN, G. 1875. Etude microscopique des mames du Lias moyen d'Essey-les-Nancy, zone inferieure de I'assise a
Manuscript received June 21, 1993 Manuscript accepted January 3, 1994
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