Tournaisian - Senckenberg

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N. Jb. Geol. Paläont. Abh. 278/1 (2015), 23–45Article Stuttgart, October 2015

Tournaisian (Lower Mississippian) bryozoans from Belgium Zoya Tolokonnikova, Andrej Ernst, and Edouard Poty With 9 figures

Abstract: Ten bryozoan species are described from the Tournaisian of Namur-Dinant Basin, Belgium. Five species are new: Leptotrypa hexagona sp. nov., Dyscritella ornata sp. nov., Saffordotaxis spinigerus sp. nov., Paranicklesopora ornaisa sp. nov., and Spinofenestella nodosa sp. nov. One species Rectifenestella rudis (Ulrich, 1890) is characterised by wide geographical and stratigraphical distribution. Four species are described in open nomenclature: Fistulipora sp. 1, F. sp. 2, Nikiforovella sp., Trepostomata sp. indet. The bryozoan assemblage of Belgium shows palaeogeographical connections with Tournaisian assemblages from some regions of Eurasia and USA. Key words: Tournaisian, Belgium, Bryozoa, taxonomy, palaeobiogeography.

& Allison 1998; Taylor & James 2013). During the Carboniferous, bryozoans were diverse and widely distributed (Ross 1981, Ernst 2013, Tolokonnikova et al. 2014). Bryozoan faunas are well studied in various parts of the world. The existing knowledge of Tournaisian bryozoans of southern Belgium is very scarce. Some two dozens of fenestrate and cryptostome species were described by De Koninck (1842-1844), Demanet (1923, 1938), and Kaisin (1942). The majority of these species remain inadequately characterized because the descriptions were made on the external colony shape. No information about the internal morphology was provided by earlier authors, which is tremendously important for the provision of detailed and accurate systematic treatments and taxonomic identifications. Analysis of facies with bryozoans from Waulsortian buildups of Tournaisian age in southern Belgium has been done by Lees (1988, 2006) and Wyse Jackson (2006), while McKinney et al. (1987) have examined the role of fenestrate bryozoans as sediment bafflers in these buildups. The aim of the present paper is the description of bryozoan assemblages from several formations of the Lower Tournaisian (Hastarian) and the lower part of the

1. Introduction

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The Tournaisian as a stratigraphic unit has been established originally in southern Belgium (Dumont 1832). At present, significant knowledge about geology and palaeontology of the investigated area, which became classical in the study of the Carboniferous deposits, has been gathered. Diverse marine fauna were described here, among them foraminifers, conodonts and rugose corals are important for regional and international biostratigraphy (e.g., Conil 1968; Conil et al. 1991; Poty 1981; Groessens 1975; Webster & Groessens 1991; Poty et al. 2006, 2011, 2014). Miospore assemblages are also used for division of the basal Tournaisian deposits (Higgs et al. 1992). However, in various cases the mentioned groups of fossils cannot be helpful for interregional correlation because of their insufficient study or due to different facies in other regions. Therefore, the knowledge about other groups is also necessary. Tournaisian deposits of southern Belgium are rich in macrofossils: brachiopods, corals, bryozoans, crinoids, gastropods etc. Bryozoans represent a group of benthic marine animals with a significant potential for application in various fields of palaeoecology and biostratigraphy (e.g., Bancroft 1987; Smith 1995; Tay©2015 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany

DOI: 10.1127/njgpa/2015/0515

www.schweizerbart.de

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Zoya Tolokonnikova et al.

Fig. 1. A – Schematic map with bryozoan localities in Belgium. B – field photographs from selected localities.

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Tournaisian (Lower Mississippian) bryozoans from Belgium 25

Fig. 2. Bryozoan distribution in the Tournaisian of the Namur-Dinant Basin.

sections from cores of boreholes Rekkem-2 (Belgian Geological Survey reference 96E76) (depths 190.1, 190.7, 191.1, 196.0, 197.9 and 199.9 m) and Bossuit K (Belgian Geological Survey 97E866) (depths 101.4, 105.3, and 124.25 m), as well as from rock samples from localities La Belle Roche quarry (bc 10, bc 3b; collected 2008) and Nutons quarry (bc 22, 25, 29; collected 2011; Yvoir Fm. base bc 2; collected 2012). At these localities, bryozoans were found in nodular, argillaceous limestones. In the Les Ornais quarry bryozoans are locally abundant, associated with brachiopods and crinoids (Fig. 1B). The investigated bryozoans were studied in thin sections using a transmitted light binocular microscope. In total 84 thin sections were studied. Morphological character terminology is adopted from Anstey & Perry (1970) for trepostomes, Hageman (1993) for cryptostomes, and Snyder (1991) for fenestrates. All the studied material is housed at the Department of Geology of the University of Liège (prefix: ULg).

Upper Tournaisian (Ivorian) of the Namur-Dinant Basin and their comparison with contemporaneous faunas of different parts of the world.

2. Materials and methods Material for study comes from the Namur-Dinant Basin (Fig. 1A). Part of the studied material was collected by the authors in 2013 from the Anseremme railway cutting (bed 239: N 50°14.466, E 04°54.683), Nutons quarry (interval of beds 115-116: N 50°19.737, E 04°59.004, and interval of beds 118-125: N 50°19.737, E 04°59.004 ), and Les Ornais quarry (beds 4-1, 4-2, and 4-3: N 50°27.033, E 05°17.750’). From these samples 61 thin sections were prepared. The study has been complemented by collections of lithological and coral thin sections of Edouard Poty deposited in the collections of paleontology (Department of Geology) of the University of Liège (23 thin sections). These collections include thin

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Fig. 3.

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3. Geological setting

Stratigraphical and geographical ranges: Ordovician to Permian; worldwide.

The Tournaisian of southern Belgium is distributed on both sides of the Midi-Eifel fault zone in the Namur Synclinorium (part of the Brabant Parautochtone of Hance et al. 1999) and in the Dinant Synclinorium (part of the Ardenne Allochtone of the same authors). These structural units were part of the Namur-Dinant Basin during the time of deposition, which is composed of different sedimentation areas (Poty 1997; Hance et al. 2001). The studied localities belong to the Dinant sedimentation area (Anseremme railway cutting), the Condroz sedimentation area (Nutons, Les Ornais and La Belle Roche quarries) and the eastern part of the Hainaut sedimentation area (Rekkem-2 and Bossuit K boreholes). About the stratigraphical position of the samples studied here, there are no significant differences between these sedimentation areas and they can be positioned in the same lithostratigraphical scale (Fig. 2). The chrono, bio and sequence stratigraphical scales used here are those of Poty et al. (2014).

Fistulipora sp. 1 Fig. 3A-D; Appendix Material: ULg 7-7a-e. Description: Encrusting colonies, 0.48 to 1.17 mm in thickness. Autozooecia growing from thick epitheca, bending sharply at their bases towards colony surface. Autozooecial apertures circular to oval. Basal diaphragms common, thin, horizontal or inclined. Lunaria well developed, triangular to horseshoe shaped. Vesicles moderate in size, separating autozooecia in 1-2 rows, polygonal in tangential section, boxlike to hemispheric, with plane or slightly concave roofs, 8-9 arranged around each autozooecial aperture. Autozooecial walls thick, laminated. Comparison: The present species is similar to Fistulipora usitata Gorjunova & Morozova, 1979 from the upper Tournaisian-Viséan of Mongolia having similar arrangement of vesicles and close aperture widths (0.18-0.32 mm vs. 0.22-0.34 mm in F. usitata). The present species is also similar to Fistulipora djeskazganica Nekhoroshev, 1953 from the upper Tournaisian of Kazakhstan, but differs from it by smaller apertures (0.18-0.32 mm vs. 0.30-0.33 mm in F. djeskazganica).

4. Systematic palaeontology Phylum Bryozoa Ehrenberg, 1831 Class Stenolaemata Borg, 1926 Superorder Palaeostomata Ma et al., 2014 Order Cystoporata Astrova, 1964 Suborder Fistuliporina Astrova, 1964 Family Fistuliporidae Ulrich, 1882 Genus Fistulipora M’Coy, 1849

Stratigraphical and geographical ranges: Hastière and Pont-d’Arcole Formations, Hastarian substage, Tournaisian, Mississippian; Anseremme cut, Belgium.

Fistulipora sp. 2 Fig. 3E-F; Appendix

Type species: Fistulipora minor M‘Coy, 1849. Carboniferous; England.

Material: ULg 6-1a (only tangential section). Description: Encrusting colony, thickness unknown. Autozooecia growing from thick epitheca, bending sharply at their bases towards colony surface. Autozooecial apertures circular to oval. Basal diaphragms common, thin, horizontal or inclined. Lunaria poorly developed, horseshoe shaped. Vesicles moderate in size, separating autozooecia in 1-2 rows, polygonal in tangential section, box-like to hemispheric, with plane or slightly concave roofs, 8-9 arranged around each autozooecial aperture. Autozooecial walls thick, laminated.

Diagnosis: Massive, encrusting, or branched colonies. Cylindrical autozooecia with thin walls and complete diaphragms. Apertures rounded, with horseshoe-shaped lunaria. Autozooecia separated by extrazooidal vesicular skeleton. Maculae often developed. Comparison: Fistulipora M‘Coy, 1849 differs from Eridopora Ulrich, 1882 in having rounded, horseshoe-shaped lunaria instead of triangular ones. Furthermore, Eridopora develops persistently encrusting colonies, whereas Fistulipora may also develop massive and branched colonies.

Comparison: The present specimen differs from Fistulipora tubulosa Nikiforova, 1933 from the Lower Carboniferous of Turkmenistan in smaller autozooecial apertures (0.19-0.25

Fig. 3. A-D – Fistulipora sp. 1. A – Tangential section showing autozooecia and vesicles, ULg 7-7a. B – Tangential section showing lunaria, ULg 7-7a. C – Longitudinal section, ULg 7-7a. D – Longitudinal section, ULg 7-7c. E-F – Fistulipora sp. 2. E – Tangential section showing autozooecia and vesicles. F – Tangential section, ULg 6-1a.

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mm vs. averagely 0.30 mm in F. tubulosa). It is also similar to the species Fistulipora aff. incrustans (Phillips, 1836) described by Nekhoroshev (1953) from the upper Tournaisian of Kazakhstan. The two species have thin encrusting colonies, 1-2 rows of vesicles between apertures and similar autozooecial width (0.19-0.25 mm vs. 0.21-0.27 mm in F. aff. incrustans). However, the original species Fistulipora incrustans (Phillips, 1836) has significantly larger autozooecial apertures (0.27-0.40 mm). Unfortunately, the material of Nekhoroshev (1953) was studied externally, without thin sections, so its internal morphology is unknown.

Type locality: Anseremme cut, Belgium. Type horizon: Pont-d’Arcole Formation, Hastarian substage, Tournaisian, Mississippian. Diagnosis: Encrusting colonies; autozooecial apertures polygonal; exilazooecia rare; 3-6 acanthostyles surrounding each autozooecial aperture; maculae consisting of macrozooecia. Description: Encrusting colonies, 0.48-0.72 mm in thickness. Autozooecia budding from a thin epitheca, growing a short distance parallel to the substrate, then bending sharply to the colony surface. Autozooecial apertures hexagonal. Exilazooecia rare, 0.050-0.065 mm in diameter. Acanthostyles common, 3-6 surrounding each autozooecial aperture. Autozooecial walls finely laminated, 0.010-0.015 mm thick in endozone; laminated, merged without visible autozooecial boundaries, 0.06-0.08 mm thick in exozone. Maculae consisting of macrozooecia, 0.7-1.0 mm in diameter. Macrozooecial apertures 0.26-0.29 mm in diameter, spaced 0.36-0.41 mm from centre to centre.

Stratigraphical and geographical ranges: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Nutons quarry, Belgium.

Order Trepostomata Ulrich, 1882

Suborder Amplexoporina Astrova, 1965 Family Atactotoechidae Duncan, 1939 Genus Leptotrypa Ulrich, 1883 [= Calacanthopora Duncan, 1939]

Comparison: Leptotrypa hexagona sp. nov. differs from L. fistulosa Lavrentjeva, 1970 by thicker colonies (0.48-0.72 mm vs. 0.25-0.35 mm in L. fistulosa), thicker autozooecial walls in exozone (0.06-0.08 mm vs. 0.04 mm in L. fistulosa), larger acanthostyles ( 0.03-0.06 mm vs. 0.02-0.03 mm in L. fistulosa), as well as by rare exilazooecia.

Type species: Leptotrypa minima Ulrich, 1883. Cincinnatian (Upper Ordovician); North America. Diagnosis: Thin encrusting colonies. Autozooecia with polygonal apertures. Autozooecial walls irregularly thickened throughout the colony or near the periphery, indistinctly laminated, usually integrated in initial parts and merged near the colony surface. Autozooecial diaphragms absent or rare. Exilazooecia rare to common. Acanthostyles small to moderately large, common to abundant (modified after Astrova, 1978).

Stratigraphical and geographical ranges: Pont-d’Arcole Formation, Hastarian substage, Tournaisian, Mississippian; Anseremme cut, Belgium.

Family Dyscritellidae Dunaeva & Morozova, 1967 Genus Dyscritella Girty, 1911

Comparison: Leptotrypa Ulrich, 1883 differs from Anomalotoechus Duncan, 1939 in having thin encrusting colony and rare diaphragms.

Type species: Dyscritella robusta Girty, 1911. Mississippian (Lower Carboniferous); Arkansas, USA.

Stratigraphical and geographical ranges: Middle Ordovician to Middle Carboniferous; worldwide.

Diagnosis: Dendroid and encrusting colony with abundant acanthostyles and exilazooecia. Autozooecia parallel to longitudinal direction of the colony in endozone; gradually bending outward in exozone. Diaphragms in autozooecia lacking or very rare; lacking in exilazooecia. Exilazooecia circular to angular in cross section and separated from the autozooecia and from each other by thick walls. Two sizes of acanthostyles may be present. Zooecial walls thin in endozone, rapidly thickening in the exozone (modified after Ernst & Gorgij 2013).

Leptotrypa hexagona sp. nov. Fig. 4A-D; Appendix Etymology: The species name refers to regular hexagonal shape of apertures. Holotype: ULg 7-7b.

Comparison: Dyscritella Girty, 1911 generally lacks diaphragms which are commonly developed in the similar

Paratypes: ULg 7-7c-e.

Fig. 4. A-D – Leptotrypa hexagona sp. nov. A-B – tangential section, ULg 7-7b. C-D – Longitudinal section, paratype ULg 7-7c. E-G – Dyscritella ornata sp. nov., holotype ULg 6-2b. E-F – Tangential section. G – Longitudinal section.

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Fig. 4.

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genus Dyscritellina Morozova in Dunaeva & Morozova, 1967. Furthermore, Dyscritellina has extremely large acanthostyles, which are absent in Dyscritella.

zooecial aperture in D. clara; acanthostyle diameter 0.0150.060 mm vs. 0.06-0.08 mm in D. clara). Stratigraphical and geographical ranges: Pont-d’Arcole Formation, Hastarian substage, Tournaisian, Mississippian; Anseremme cut and Les Ornais quarry; Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Nutons quarry, Belgium.

Stratigraphical and geographical ranges: Devonian to Triassic; worldwide.

Dyscritella ornata sp. nov. Figs. 4E-G, 5A-C; Appendix

Incertae sedis Family uncertain Genus uncertain Trepostomata sp. indet. Figs. 5D-H, 6A; Appendix

Etymology: The species name refers to abundant exilazooecia which produce an ornamentation on the colony surface. Holotype: ULg 6-2b. Paratypes: ULg 4-3a-1, 4-3a-6, 6-2e, i, 7-7e.

Material: Single colony ULg 4-2a-(1-4).

Type locality: Nutons quarry, Belgium.

Description: Branched colony, 4.45-4.85 mm in diameter, with 0.36-0.40 mm wide exozones and 3.73-4.05 mm wide endozones. Autozooecial apertures oval. Autozooecial diaphragms common to abundant in the transition between endozone and exozone, straight, thin. Autozooecial walls laminated, 0.03-0.05 mm thick in endozone; with serrated dark zooecial boundaries at the base of exozone and merged in the outer part of exozone, 0.11-0.14 mm thick in exozone. Acanthostyles and exilazooecia rare. Heterostyles common, arranged in 1-3 irregular rows between autozooecia, 0.0130.020 mm in diameter. Maculae not observed.

Type horizon: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian. Diagnosis: Encrusting and branched colonies with moderately wide exozones; autozooecial diaphragms absent; exilazooecia abundant, 3-10 surrounding each autozooecial aperture; acanthostyles common, 2-8 surrounding each autozooecial aperture; autozooecial walls laminated, moderately thick in exozone; maculae not observed. Description: Encrusting and branched colonies Encrusting colonies 0.26-0.66 mm in thickness. Branched colonies 0.75-1.00 mm in diameter, with 0.18-0.26 mm wide exozones and 0.39-0.48 mm wide endozones. Autozooecia budding from a thin epitheca, growing a short distance parallel to the substrate, then bending sharply to the colony surface. In a branched colony autozooecia diverging at low angles in exozone. Autozooecial diaphragms absent. Autozooecial apertures polygonal. Exilazooecia abundant, 3-10 surrounding each autozooecial aperture, originating at the base of exozone. Acanthostyles common, 2-8 surrounding each autozooecial aperture. Autozooecial walls finely laminated, 0.010-0.015 mm thick in endozone; laminated, merged without visible autozooecial boundaries, 0.020-0.045 mm thick in exozone. Maculae not observed.

Comparison: The present material does not fit completely to any known genus. Acanthostyles, abundant heterostyles and merged autozooecial walls make it similar to some species of the genus Stenophragmidium Bassler, 1952 (Cleary & Wyse Jackson 2007). However, species of Stenophragmidium possess hemiphragms. The heterostyles resemble paurostyles (simple styles without laminated core sensu Blake (1983)). Similar styles occur in the genus Boardmanella Gorjunova & Weis, 2003. However, Boardmanella possesses variously sized paurostyles and no true acanthostyles. Furthermore, the autozooecial wall in Boardmanella is uniformly merged, whereas the walls in the present material are serrated in the basal part of exozone. The heterostyles in the present material can be also interpreted as tubules which occur in eridotrypellid bryozoans, such as Eridotrypella Duncan, 1939. However, tubules in eridotrypellids are usually smaller, and these bryozoans have merged autozooecial walls with laminated singulum.

Comparison: Dyscritella ornata sp. nov. differs from D. clara (Trizna, 1958) from the upper Tournaisian of Kuznets Basin by absence of diaphragms, thinner branched colonies (branch diameter 0.75-1.00 mm vs. 3.3 mm in D. clara), smaller apertures (autozooecial width 0.09-0.18 mm vs. 0.160.24 mm in D. clara), and by more abundant and smaller acanthostyles (2-8 vs. 3-4 acanthostyles around each auto-

Stratigraphical and geographical ranges: Yvoir Formation (Basal Hun Member), Hastarian substage, Tournaisian, Mississippian; Les Ornais quarry, Belgium.

Fig. 5. A-C – Dyscritella ornata sp. nov., paratype ULg 6-2i. A – Tangential section. B – Longitudinal section. C – Tangential section showing exilazooecia and acanthostyles. D-H – Trepostomata sp. indet. D-E – Branch transverse section, ULg 4-2a-1. F – Longitudinal section, ULg 4-2a-2. G-H – Tangential section showing acanthostyles (arrow) and paurostyles, ULg 4-2a-4.

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Fig. 5.

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Order Cryptostomata Vine, 1884 Suborder Rhabdomesina Astrova & Morozova, 1956 Family Nikiforovellidae Gorjunova, 1975 Genus Nikiforovella Nekhoroshev, 1948

the lower Tournaisian of Kazakhstan, but differs from it by larger metazooecia (0.03-0.07 mm vs. 0.020-0.025 mm in N. alternata), and more acanthostyles arranged between longitudinally successive apertures (4-5 vs. 2 in N. alternata). Stratigraphical and geographical ranges: Upper Member of the Hastière Formation, Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Nutons quarry, Belgium. Hastière Formation, Hastarian substage, Tournaisian, Mississippian; Bossuit K borehole, Belgium.

Type species: Nikiforovella alternata Nekhoroshev, 1948, by original designation. Mississippian (Lower Carboniferous); Altai, Russia. Diagnosis: Branched colonies. Autozooecia diverging at low angles from distinct median axis. Hemisepta absent, diaphragms rare. Autozooecial walls laminated, with dark zooecial boundaries. Metazooecia few between longitudinally successive autozooecial apertures; acanthostyles common to abundant. Longitudinal ridges absent.

Family Rhomboporidae Simpson, 1895 Genus Saffordotaxis Bassler, 1952 Type species: Rhombopora incrassata Ulrich, 1890. Lower Mississippian; USA (Kentucky).

Comparison: Nikiforovella Nekhoroshev, 1948 is similar to Streblotrypella Nikiforova, 1948, but differs from it mainly in the shape of autozooecia, which bend at higher angles in exozone, and in the absence of longitudinal ridges. Moreover, styles can be absent in Streblotrypella.

Diagnosis: Branched colonies with distinct linear axis. Endozones and exozones distinctly separated. Autozooecia with oval apertures and regularly thickened walls in the exozone, diverging at angles of 20-30° from the axis, bending sharply in exozones and intersecting the colony surface at angles of 80-90°; polygonal in endozone becoming hexagonal and rounded at colony surface. Longitudinal arrangement of autozooecia regular. Diaphragms complete, rare. Hemisepta absent. Metazooecia and acanthostyles absent. Aktinotostyles common to abundant, arranged in single or multiple rows, arising in the exozone.

Stratigraphical and geographical ranges: Devonian to Permian; worldwide.

Nikiforovella sp. Fig. 6B-E; Appendix

Comparison: Saffordotaxis Bassler, 1952 differs from Primorella Romantchuk & Kiseleva, 1968 in shape of autozooecia with sharp bend in the exozone.

Material: ULg Bossuit K/124.25; Nutons 2011, bc 25. Description: Branched colonies, 0.8-1.9 mm in diameter, with 0.15-0.40 mm wide exozones and 0.5-1.1 mm wide endozones. Autozooecia growing in spiral pattern from the median axis, rhombic in the transverse section of endozone, abruptly bending in exozone. Autozooecial apertures oval to circular, arranged in regular diagonal rows. Autozooecial diaphragms absent. Metazooecia originating at the base of exozone, 2-3 arranged between longitudinally successive autozooecial apertures. Acanthostyles 0.02-0.025 mm in diameter, 4-5 arranged between longitudinally successive autozooecial apertures, having distinct hyaline cores and laminated sheaths. Autozooecial walls granular, 0.005-0.008 mm thick in endozone; finely laminated, without visible zooecial boundaries in exozone.

Stratigraphical and geographical ranges: Middle Devonian to Lower Permian; worldwide.

Saffordotaxis spinigerus sp. nov. Figs. 6F-I, 7A; Appendix Etymology: The species name refers to large aktinotostyles (from Latin “spiniger” – spiny). Holotype: ULg 4-1b-1 Paratypes: ULg Rekkem-2 (depths 196.0, 199.9, 191.1, 197.9, 190.7, 190.1 m); Bossuit K (depths 101.4, 105.3 m); La Belle Roche quarry 2008, bc 10, bc 3b; Nutons 2011 – bc 29; Nutons quarry 2012 - Yvoir Fm. base bc 2; ULg 4-3a-(1, 3, 5-6), 4-3e-(1-2, 5-6), 4-3d-(1-2, 4), 4-3b-(1-4, 6), 4-3c-(1-2), 4-1d(1-2), 4-1b-2; ULg 6-2c, d, g, h, j, k, m, n, o.

Comparison: The present material differs from Nikiforovella kasakhstanica Nekhoroshev, 1948 from Tournaisian of Kazakhstan in smaller acanthostyles (0.02-0.025 mm vs. 0.05 mm in N. kasakhstanica). The present species is also similar to Nikiforovella alternata Nekhoroshev, 1956 from

Fig. 6. A – Trepostomata sp. indet., ULg 4-2a-2. A – Longitudinal section. B-E – Nikiforovella sp., ULg Bossuit KUL/124.25. B-D – Longitudinal section. E – Tangential section showing autozooecial apertures, metazooecia and acanthostyles. F-I – Saffordotaxis spinigerus sp. nov. F-G – Longitudinal section, ULg 4-1b-1. H – Tangential section, holotype ULg 4-1b-1. I – Tangential section, paratype ULg 4-3a-6.

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Fig. 6.

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Type locality: Les Ornais quarry, Belgium.

boundaries. Metazooecia absent. Acanthostyles and/or paurostyles present, forming a regular pattern around autozooecial apertures.

Type horizon: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian.

Comparison: Paranicklesopora Gorjunova, 1988 differs from Nicklesopora Bassler, 1952 by the presence of superior and inferior hemisepta and acanthostyles.

Diagnosis: Thin branched colonies with narrow exozones; autozooecia budding at angles of 21–37° in endozones, abruptly bending in exozones; rhombic, tear-drop shaped in transverse section of endozone; autozooecial apertures oval, arranged in regular diagonal rows on branches; large aktinotostyles in a single row between autozooecia.

Stratigraphical and geographical ranges: Mississippian; Mongolia, Transcaucasia, Europe. Kuznets Basin.

Description: Branched colonies, 0.7-1.0 mm in diameter, with 0.15-0.40 mm wide endozones and 0.22-0.41 mm wide exozones. Autozooecia tubular, growing in spiral pattern from the distinct median axis at angles of 21–37° in endozones, abruptly bending in exozones; having a rhombic, tear-drop shape in transverse section of endozone. Autozooecial apertures oval, arranged in regular diagonal rows on branches. Autozooecia diaphragms occasionally present. Aktinotostyles large, arranged in a single row between autozooecia. Autozooecial walls finely laminated, with dark dividing layer, 0.005-0.008 mm thick in endozone; laminated, without distinct boundaries in exozone.

Paranicklesopora ornaisa sp. nov. Figs. 7B-G, 8A-B; Appendix Etymology: The species name refers to name of Les Ornais quarry where it was found. Holotype: ULg 4-3d-2. Paratypes: ULg 4-3b-6, 4-3a-5, 4-1d-(1-2), 4-1b-1, 4-3a-(1-3, 5-6), 4-1c-1, 4-1e-4, 4-3d-(1, 3). Type locality: Les Ornais quarry, Belgium.

Comparison: Saffordotaxis spinigerus sp. nov. differs from S. germanа Ariunchimeg, 2005 from the Viséan of Mongolia by smaller apertures (0.07-0.11 mm vs. 0.14 mm in S. germanа), by size and location of aktinotostyles (0.04-0.07 mm in a single row vs. 0.02 mm in several rows or irregularly in S. germanа), and by presence of diaphragms.

Type horizon: Yvoir Fm. (Hun Member), Hastarian substage, Tournaisian, Mississippian. Diagnosis: Thin branched colonies with narrow endozones and occasional secondary overgrowths; autozooecia tubular, growing from a central bundle of zooecia, abruptly bending in exozones; superior hemisepta long, hook-shaped, curved proximally; inferior hemisepta long, situated beneath superior hemisepta; acanthostyles and paurostyles abundant.

Stratigraphical and geographical ranges: Pont d’Arcole Formation, Hastarian substage, Tournaisian, Mississippian; Bossuit K borehole, Belgium. Orient Formation, Upper Hastarian substage, Tournaisian, Mississippian; Rekkem-2 borehole, Belgium. Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Nutons and Les Ornais quarries, Belgium. Ourthe Formation, Ivorian substage, Tournaisian, Mississippian; La Belle Roche quarry, Belgium.

Description: Branched colonies, 0.70-1.35 mm in diameter, with 0.27-0.91 mm wide endozones and 0.14-0.28 mm wide exozones. Secondary overgrowths occurring, 0.24-0.28 mm thick. Autozooecia tubular, growing from a central bundle of zooecia, abruptly bending in exozones, having polygonal shape in transverse section of endozone. Superior hemisepta long, hook-shaped, curved proximally; inferior hemisepta long, situated beneath superior hemisepta. Autozooecial apertures oval, arranged in regular diagonal rows on branches. Acanthostyles having hyaline cores and laminated sheaths, abundant, arranged in 1-3 rows between autozooecia. Paurostyles scattered between acanthostyles. Autozooecial walls finely laminated, 0.001-0.005 mm thick in endozone; laminated, with dark dividing layer in exozones.

Family Goldfussitrypidae Gorjunova, 1985 Genus Paranicklesopora Gorjunova, 1988 Type species: Paranicklesopora elenae Gorjunova, 1988. Mississippian (Viséan); Mongolia. Diagnosis: Branched colonies. Autozooecia diverging at low angles in endozone, often forming a central bundle. Superior and inferior hemisepta present. Autozooecial diaphragms rare. Autozooecial walls laminated, with dark zooecial

Comparison: Paranicklesopora ornaisa sp. nov. differs from P. stupenda Gorjunova in Gorjunova & Lavrentjeva,

Fig. 7. A – Saffordotaxis spinigerus sp. nov., paratype ULg 4-3a-7. A – Branch transverse section. B-G – Paranicklesopora ornaisa sp. nov. B-C – Branch transverse section, paratype ULg 4-3a-3. D – Oblique sections, holotype ULg 4-3d-2. E-F – Tangential section showing autozooecial apertures, acanthostyles and paurostyles, holotype ULg 4-3d-2. G – Longitudinal section, holotype ULg 4-3d-2.

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Fig. 7.

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2007 from the Tournaisian of Azerbaijan in having a wider exozone (0.14-0.28 mm vs. 0.07-0.10 mm in Р. stupendа ), secondary overgrowths, and smaller autozooecial apertures (aperture width 0.04-0.07 mm vs. 0.07-0.08 mm). Furthermore, Paranicklesopora ornaisa possesses acanthostyles 0.01-0.04 mm in diameter, which are arranged in 1-3 rows between autozooecial apertures, whereas aktinotostyles in P. stupenda are arranged irregularly on the colony surface. Gorjunova (in Gorjunova & Lavrentjeva, 2007) gave the value by 2 µm (0.002 mm) for the aktinotostyle diameter in P. stupenda. However, this value appears to us not realistic, because it can be compared with diameter of paurostyles which are simple structureless styles (Blake 1983). Paurostyles in Paranicklesopora ornaisa sp. nov. are 0.001-0.005 mm in diameter.

Etymology: The species name refers to abundant and diverse nodes of the new species. Holotype: ULg 4-1g-1. Paratypes: ULg 4-1a-1, 4-3a-4. Type locality: Les Ornais quarry, Belgium. Type horizon: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian. Diagnosis: Reticulate colony with moderately coarse meshwork; dissepiments narrow; fenestrules oval to rectangular; autozooecia in two rows on branches with occasional insertion of the third row before bifurcation; autozooecia triangular to trapezoid in mid tangential section; axial wall between autozooecial rows strongly zigzag; hemisepta absent; apertures circular with a single node; 4-7 apertures per fenestrule length; keel low, with moderately large nodes; large nodes on the reverse colony surface.

Stratigraphical and geographical ranges: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Les Ornais quarry, Belgium.

Order Fenestrata Elias & Condra, 1957 Suborder Fenestellina Astrova & Morozova, 1956 Family Fenestellidae King, 1849 Genus Spinofenestella Termier & Termier, 1971

Exterior description: Reticulate colony formed by straight branches joined by narrow dissepiments. Fenestrules oval to rectangular, long, narrow. Autozooecia arranged in two rows on branches. Occasionally three rows of apertures developed for the length of a fenestrule. Autozooecial apertures circular, with low smooth peristome; 4 to 7 apertures spaced per fenestrule length. Single node developed at aperture, 0.020.03 mm in diameter. Moderately large elliptical nodes on the low keel, widely spaced. Irregularly arranged sharp nodes on the reverse side of branches.

Type species: Fenestella spinulosa Condra, 1902 by subsequent designation (Morozova 1974). Upper Carboniferous, Coal Measure; Nebraska, USA. Diagnosis: Zoarium fan-shaped or conical. Branches straight, connected by thin dissepiments. Two rows of autozooecia per branch, overlapped basally. Autozooecial chambers triangular in deep tangential section, oval right below the distal tube. Chambers circular in cross-section. Proximal hemisepta absent or poorly developed. Low keel with a single row of nodes on the observe surface.

Interior description: Autozooecia short, triangular to trapezoid in mid tangential section; with short vestibule in longitudinal section. Axial wall between autozooecial rows strongly zigzag; aperture positioned at distal end of chamber. Hemisepta absent. Internal granular skeleton thin, continuous with obverse keel, nodes, peristome and across dissepiments. Outer laminated skeleton thin. Abundant microstyles in the laminated skeleton, having distinct hyaline cores and dark laminated sheaths, 0.005-0.007 mm in diameter.

Comparison: Alternifenestella Termier & Termier, 1971 is a synonym of Spinofenestella due to the close morphological similarities of their type species, according to Hageman & McKinney (2010), and Gorjunova & Weis (2012) retained Alternifenestella as a valid genus.

Comparison: Spinofenestella nodosa sp. nov. differs from S. undulata Troizkaya, 1975 from the Kassinski Horizon (lower Tournaisian) of Kazakhstan in thicker branches (0.36-0.62 mm vs. 0.25-0.30 mm in S. undulata) and larger fenestrules (0.23-0.60 х 0.78-1.73 mm vs. 0.25-0.31 x 0.63-0.73 mm in S. undulata). The new species differs from all Tournaisian species of Spinofenestella in having a larger number of apertures per fenestrule and by development of large nodes on branches.

Stratigraphical and geographical ranges: Silurian to Upper Permian; worldwide.

Spinofenestella nodosa sp. nov. Fig. 8C-H; Appendix

Fig. 8. A-B – Paranicklesopora ornaisa sp. nov. A – Longitudinal section, paratype ULg 4-1b-1. B – Longitudinal section (arrow – inferior hemiseptum), paratype ULg 4-3a-1. C-H – Spinofenestella nodosa sp. nov. C-D – Tangential section, holotype ULg 4-1g-1. E-H – Tangential section (G, apertural node – arrow), paratype ULg 4-1a-1. I – Rectifenestella rudis (Ulrich, 1890), ULg 6-2e. I – Tangential section.

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Fig. 8.

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Fig. 9. A-E – Rectifenestella rudis (Ulrich, 1890). A-B – Tangential section showing branches, fenestrules, autozooecial chambers and apertures, ULg 6-2e. C – Mid-tangential section showing place of dichotomy, ULg 6-2e. D – Tangential section showing autozooecial aperture containing apertural nodes, ULg 6-2a. E – Branch transverse section showing autozooecial chambers and low keel, ULg 6-2a.

Stratigraphical and geographical ranges: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Les Ornais quarry, Belgium.

triangular to pentagonal in mid-tangential section. Superior hemisepta present; inferior hemisepta absent. Narrow keel with one row of intermediate-sized nodes.

Genus Rectifenestella Morozova, 1974

Comparison: Rectifenestella differs from Laxifenestella Morozova, 1974 in the pentagonal shape of the autozooecia in mid-tangential section and in the absence of inferior hemisepta.

Type species: Fenestella medvedkensis Schulga-Nesterenko, 1951. Kasimovian (Upper Carboniferous); Russian Platform.

Stratigraphical and geographical ranges: Early Devonian to Late Permian; worldwide.

Diagnosis: Reticulate colonies consisting of fine to moderately robust branches and straight dissepiments. Autozooecia

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Rectifenestella rudis (Ulrich, 1890) Figs. 8I, 9A-E; Appendix

(aperture width 0.08-0.11 mm vs. 0.14 mm in R. cesteriensiformis).

1890 Fenestella rudis Ulrich, p. 537, pl. 49, fig. 3-3d. 1926 Fenestella rudis Ulrich, 1890. – Nekhoroshev, p. 1242, pl. 19, figs. 7-8, pl. 20, fig. 5. 1927 Fenestella rudis Ulrich, 1890. – Nikiforova, p. 178, pl. 4, figs. 2, 3. 1932 Fenestella rudis Ulrich, 1890. – Nekhoroshev, p. 53, pl. 2, fig. 2. 1933 Fenestella rudis Ulrich, 1890. – Nikiforova, p. 18, pl. 4, figs. 11-13. 1948 Fenestella rudis Ulrich, 1890. – Nikiforova, p. 23, pl. 6, fig. 3. 1950 Fenestella rudis Ulrich, 1890. – Nikiforova, p. 109, pl. 2, fig. 1, pl. 9, fig. 2. 1956 Fenestella rudis Ulrich, 1890. – Nekhoroshev, p. 153, pl. 18, figs. 1, 3. 1958 Fenestella rudis Ulrich, 1890. – Trizna, p. 127, pl. 34, fig. 5, pl. 35, figs. 1-4. 1973 Fenestella rudis Ulrich, 1890 multinodosa TavenerSmith, 1973. – Tavener-Smith, p. 424, pl. 6, figs. 1-7. 1979 Rectifenestella rudis (Ulrich, 1890). – Gorjunova & Morozova, p. 55, pl. 16, fig. 2. 1981 Rectifenestella rudis (Ulrich, 1890). – Morozova, p. 63, pl. 14, fig. 5. 1991 Cubifenestella rudis (Ulrich, 1890). – Snyder, p. 90, pl. 29, figs. 1-11, pl. 30, figs. 1-7. 1999 Rectifenestella rudis (Ulrich, 1890). – Lu, p. 158, pl. 5, figs. 6-8. 2000 Rectifenestella rudis (Ulrich, 1890). – Popeko, p. 100, pl. 6, fig. 2.

Stratigraphical and geographical ranges: Yvoir Formation (Hun Member), Hastarian substage, Tournaisian, Mississippian; Nutons quarry, Belgium. Viséan, USA, TournaisianViséan, Eurasia.

5. Discussion Ten bryozoan species occur in the Tournaisian of the Namur-Dinant Basin. The highest diversity is observed at the transition between the lower and upper Tournaisian substages (Fig. 2). At the base of the Tournaisian (Hastière Formation) only one bryozoan species, Nikiforovella sp., was found. In the Pont-d’Arcole Formation specific composition is very poor comprising four species: Fistulipora sp. 1, Leptotrypa hexagona sp. nov., Dyscritella ornata sp. nov., and Saffordotaxis spinigerus sp. nov. The species Saffordotaxis spinigerus sp. nov. has wide stratigraphical distribution being found in the Orient, Yvoir (Hastarian) and Ourthe Formations (Ivorian). The species composition changes in the upper part of the Hastarian substage (Yvoir Formation, Hun Member). Besides the species Dyscritella ornata sp. nov. and Saffordotaxis spinigerus sp. nov. persisting from underlaying deposits, Fistulipora sp. 2, Paranicklesopora ornaisa sp. nov., Spinofenestella nodosa sp. nov., Trepostomata sp. indet., Nikiforovella sp., and Rectifenestella rudis (Ulrich, 1890) appear in the Hun Member of the Yvoir Formation. The studied bryozoans are highly endemic at the species level. The only species known from previous studies, Rectifenestella rudis (Ulrich, 1890), displays wide stratigraphical and geographical distribution (Tournaisian-Viséan of USA, Kazakhstan, Uzbekistan, Eastern Transbaikalia, Northern Urals, Kuznets Basin, Mongolia, China, Ireland, Germany, as well as Serpukhovian of northeastern Russia). These records certainly need to be revaluated; however, such an investigation has not been done yet. All genera of the studied association except Paranicklesopora are cosmopolitan, known from Ordovician/Devonian to Carboniferous/Permian. The genus Paranicklesopora was previously known from the Mississippian of Eurasia (Mongolia and Azerbaijan). Bryozoans of the genera identified in the Tournaisian of Belgium, are known from the Tournaisian deposits of Kuznets Basin (Fistulipora, Nikiforovella, Paranicklesopora, Rectifenestella), Kazakhstan (Fistulipora, Nikiforovella, Spinofenestella), China (Fistulipora,

Material: ULg 6-2a, c, e, f, i. Exterior description: Reticulate colony formed by straight branches joined by narrow dissepiments. Fenestrules oval to rectangular, long, narrow. Autozooecia arranged in two rows on branches, with an inclusion of a third row at the place of dichotomy. Autozooecial apertures circular, with low peristome containing small nodes; 4 to 5 apertures spaced per fenestrule length. Low keel with a single row of smaller nodes alternating with larger nodes. Smaller nodes 0.015-0.030 mm in diameter; larger nodes 0.05-0.07 mm in diameter. Longitudinal striation on reverse side of branches. Interior description: Autozooecia short, pentagonal to roughly rectangular in mid tangential section; with short vestibule in longitudinal section. Axial wall between autozooecial rows strongly to weakly zigzag; aperture positioned at distal end of chamber. Hemisepta absent. Internal granular skeleton thin, continuous with obverse keel, nodes, peristome and across dissepiments. Outer laminated skeleton thin. Abundant microstyles in the laminated skeleton, having distinct hyaline cores and dark laminated sheaths, 0.0050.007 mm in diameter. Comparison: Rectifenestella rudis (Ulrich, 1890) differs from R. cesteriensiformis (Nekhoroshev, 1956) from the Viséan of Kazakhstan in longer fenestrules (0.78-0.95 mm vs. 0.60-0.65 mm in R. cesteriensiformis), and smaller apertures

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– Paleontologicheskiy Zhurnal, 2: 22-31 [in Russian]. Astrova, G.G. (1965): Morphology, history of development and system of the Ordovician and Silurian Bryozoa. – Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR, 106: 1-432 [in Russian]. Astrova, G.G. (1978): The history of development, system, and phylogeny of the Bryozoa: Order Trepostomata. – Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR, 169: 1-240 [in Russian]. Astrova, G.G. & Morozova, I.P. (1956): About systematics of the order Cryptostomata. – Doklady Akademii Nauk SSSR, 110 (4): 661-664 [in Russian]. Bancroft, A.J. (1987): Biostratigraphical potential of Carboniferous Bryozoa. – Courier Forschungsinstitut Senckenberg, 98: 193-197. Bancroft, A.J. (1988): Ovicells in Rectifenestella from the Lower Carboniferous of Ireland. – Irish Journal of Earth Sciences, 9: 19-22. Bancroft, A.J. & Wyse Jackson, P.N. (1995): Revision of the Carboniferous cystoporate bryozoans Fistulipora incrustans (Phillips, 1836), with remarks on the type species of Fistulipora M’Coy 1849. – Geological Journal, 30: 129-143. Bassler, R.S. (1952): Taxonomic notes on genera of fossil and Recent Bryozoa. – Journal of the Washington Academy of Sciences, 42 (12): 381-385. Blake, D.B. (1983): Introduction to the Suborder Rhabdomesina. – In: Robison, R.A. (Ed.): Treatise on Invertebrate Paleontology, part G, Bryozoa, Revised, 1: 530-549. Borg, F. (1926): Studies on Recent cyclostomatous Bryozoa. – Zoologiska Bidrag från Uppsala, 10: 181-507. Condra, G.E. (1902): New Bryozoa from the Coal Measures of Nebraska. – The American Geologist, 30: 337-358. Cleary, D. & Wyse Jackson, P.N. (2006): Stenophragmidium Bassler, 1952 (Trepostomida: Bryozoa) from the Mississippian of Ireland and Britain. – Irish Journal of Earth Sciences, 25 (19): 1-25. Conil, R. (1968): Le calcaire carbonifère depuis le Tn1a jusqu’au V2a. – Annales de la Société géologique de Belgique, 90: 687-726. Conil, R., Groessens, E., Laloux, M., Poty, E. & Tourneur, F. (1991): Carboniferous guide foraminifers, corals and conodonts in Franco-Belgian and Campine basins: their potential for widespread correlation. – Courier Forschungsinstitut Senckenberg, 130: 15-30. Demanet, F. (1923): La Waulsortien de Sosoye et ses rapports fauniques avec le Waulsortien dage Tournaisian supérieur. – Mémoires de l’Institut Géologique de l’Université de Louvain, 2: 37-285. Demanet, F. (1938): La Faune des Couches de passage du Dinantien au Namurien dans le synclinorium de Dinant. – Mémoires de Musée Royal d’Histoire Naturelle de Belgique, 84: 1-201. Dumont, A. (1832): Mémoire sur la constitution géologique de la Province de Liège. – Mémoire couronne de l’Académie royale des Sciences, 8: 1-374. Dunaeva, N.N. & Morozova, I.P. (1967): Peculiarities of development and systematical position of some Upper Paleozoic Trepostomata. – Paleontologicheskiy Zhurnal, 4: 86-94 [in Russian]. Duncan, H. (1939): Trepostomatous Bryozoa from the Trav-

Saffordotaxis, Rectifenestella), Mongolia (Nikiforovella, Rectifenestella), USA (Fistulipora, Rectifenestella), Uzbekistan (Nikiforovella, Rectifenestella), Russian Platform (Leptotrypa, Rectifenestella), Azerbaijan (Paranicklesopora), Ireland (Dyscritella), British Isles (Fistulipora, Rectifenestella), Eastern Transbaikalia (Rectifenestella, Dyscritella, Nikiforovella), Kurgan region (Nikiforovella, Rectifenestella, Leptotrypa), and Urals (Fistulipora) (Nikiforova 1950; Nekhoroshev 1953, 1956; Trizna 1958; Lavrentjeva 1970, 1974; Troizkaya 1975; Bancroft 1988; Yang et al. 1988; Bancroft & Wyse Jackson 1995; Popeko 2000; Ariunchimeg 2010; Gorjunova & Lavrentjeva 2007).

6. Conclusions The present paper provides the first detailed taxonomic description of Tournaisian bryozoans of Belgium. The studied fauna is represented by ten bryozoans, including five new species of the cosmopolitan genera Leptotrypa, Dyscritella, Saffordotaxis, Spinofenestella and the genus Paranicklesopora with distribution in the Mississippian of Eurasia. In the Tournaisian close palaeobiogeographical connections can be traced between Belgium, USA and some regions of Eurasia on genus level. The endemism of species is 90%.

Acknowledgements Zoya Tolokonnikova thanks the Paleontological Society for financial support (PAlSIRP Sepkoski Grant 998X-14-607531). Andrej Ernst thanks the Deutsche Forschungsgemeinschaft (DFG) for financial support (project ER 278/6.1). Part of the work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University. This study is a contribution to the IGCP 596 “MidPalaeozoic climate and biodiversity”. We are grateful to Juan Luis Suàrez Andrés, Santander, and Patrick Wyse Jackson, Dublin, for their useful comments.

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Schulga-Nesterenko, M.I. (1951): Carboniferous fenestellids of the Russian Platform. Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR, 32: 1-161 [in Russain]. Simpson, G.B. (1895): Handbook of the genera of the North American Palaeozoic Bryozoa. – Annual report New York State Geology, 14: 403-669. Smith, A.M. (1995): Palaeoenvironmental interpretation using bryozoans: a review. – In: Bosence, D.W. & Allison, P.A. (Eds.): Marine palaeoenvironmental analysis from fossils. – Geological Society, Special Publications, 83: 231-243. Snyder, E.M. (1991): Revised taxonomic procedures and paleoecological implications for some North American Mississippian Fenestellidae and Polyporidae. – Palaeontographica Americana, 57: 1-275. Tavener-Smith, R. (1973): Fenestrate Bryozoa from the Visean of County Fermanagh, Ireland. – Bulletin of the British Museum (Natural History) Geology, 23 (7): 391493. Taylor, P.D. & Allison, P.A. (1998): Bryozoan carbonates through time and space. – Geology, 26 (5): 459-462. Taylor, P.D. & James, N.P. (2013): Secular changes in colony-forms and bryozoan carbonate sediments through geological history. – Sedimentology, 60: 1184-1212. Termier, H. & Termier, G. (1971): Bryozoaires du Paleozoique supérieur de lʼAfganistan. – Documents des Laboratoires de Géologie de la Faculté des Sciences de Lyon, 47: 1-52. Troizkaya, T.D. (1975): Main features of bryozoans in Central Kazakhstan at the boundary between the Devonian and the Carboniferous. – Paleontologicheskiy Zhurnal, 9: 323-339 [in Russian]. Trizna, V.B. (1958): Early Carboniferous bryozoans of the Kuznets depression. – Trudy Vsesoyuznogo Neftanogo Nauchno-Issledovatel’skogo Geologo-Razvedochnogo Instituta, 122: 1-436 [in Russian]. Tolokonnikova, Z., Ernst, A. & Wyse Jackson, P.N. (2014): Palaeobiogeography and diversification of TournaisianViséan bryozoans (lower-middle Mississippian, Carboniferous) from Eurasia. – Palaeogeography, Palaeoclimatology, Palaeoecology, 414: 200-211. Ulrich, E.O. (1882): American Palaeozoic Bryozoa. – Journal of the Cincinnati Society of Natural History, 5: 121175, 233-257. Ulrich, E.O. (1883): American Palaeozoic Bryozoa. – Journal of the Cincinnati Society of Natural History, 6: 245279. Ulrich, E.O. (1890): Palaeozoic Bryozoa: III. – Report of the Geological Survey of Illinois, 8: 283-688. Vine, G.R. (1884): Fourth report of the Committee, consisting of Dr. H. C. Sorby and Mr. G. R. Vine, appointed for the purpose of reporting on fossil Bryozoa. – In: Report of the British Association for the Advancement of Science (Southport, 1883): 161-209; London (John Murray). Webster, G.D. & Groessens, E. (1991): Conodont subdivisions of the Lower Carboniferous. – In: Brenckle, P.L. & Manger, W.L. (Eds.): Intercontinental correlation and division of the Carboniferous System. Courier Forschungsinstitut Senckenberg, 130: 31-40. Wyse Jackson, P.N. (2006): Bryozoa from Waulsortian buildups and their lateral facies (Mississippian, Carbonifer-

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Addresses of the authors:

Zoya Tolokonnikova, Kuban State University, Kazan Federal University, Krasnodar, Russia. 353235 Aphipskij, Post box demand; e-mail: [email protected] Andrej Ernst, Institut für Geologie, Universität Hamburg, Bundesstr. 55, 20146 Hamburg, Germany; e-mail: [email protected] Edouard Poty, Département de Géologie, Université de Liège, Batiment B18, Sart Tilman, 4000 Liège, Belgium; e-mail: [email protected]

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Appendix Descriptive statistics. Abbreviations: N = number of measurements, X = mean, SD = sample standard deviation, CV = coefficient of variation, Min = minimum value, Max = maximum value. Fistulipora sp. 1 Aperture width, mm Aperture spacing, mm Vesicle diameter, mm Vesicles per aperture Vesicle spacing, mm

N 20 10 10 4 10

X 0.24 0.39 0.11 8.5 0.10

SD 0.037 0.057 0.023 0.577 0.020

CV 15.35 14.62 20.53 6.79 19.50

MIN 0.18 0.32 0.08 8.0 0.07

MAX 0.32 0.48 0.16 9.0 0.13

N 13 13 20 6

X 0.22 0.49 0.12 8.2

SD 0.019 0.052 0.029 0.753

CV 8.97 10.66 24.07 9.22

MIN 0.19 0.42 0.08 7.0

MAX 0.25 0.60 0.17 9.0

N 25 25 25 25 8

X 0.18 0.25 0.05 3.60 0.07

SD 0.030 0.038 0.009 1.000 0.007

CV 16.85 15.25 18.73 27.78 9.75

MIN 0.12 0.18 0.03 3.00 0.06

MAX 0.23 0.34 0.06 6.00 0.08

N 86 81 81 81 45 53

X 0.13 0.19 0.039 0.037 4.4 6.2

SD 0.018 0.025 0.012 0.012 1.401 1.898

CV 13.86 13.22 30.85 32.50 32.16 30.48

MIN 0.09 0.14 0.015 0.018 2.0 3.0

MAX 0.18 0.25 0.060 0.070 8.0 10.0

N 30 30 12 10 10

X 0.13 0.26 0.047 0.048 0.12

SD 0.018 0.035 0.020 0.010 0.010

CV 13.66 13.38 42.12 21.20 8.41

MIN 0.10 0.20 0.025 0.030 0.11

MAX 0.18 0.34 0.08 0.065 0.14

N 11 10

X 0.14 0.05

SD 0.009 0.013

CV 6.39 27.26

MIN 0.12 0.03

MAX 0.15 0.07

Fistulipora sp. 2 Aperture width, mm Aperture spacing, mm Vesicle diameter, mm Vesicles per aperture Leptotrypa hexagona sp. nov. Aperture width, mm Aperture spacing, mm Acanthostyle diameter, mm Acanthostyles per aperture Wall thickness in exozone, mm Dyscritella ornata sp. nov. Aperture width, mm Aperture spacing, mm Acanthostyle diameter, mm Exilazooecia width, mm Acanthostyles per aperture Exilazooecia per aperture Trepostomata sp. indet. Aperture width, mm Aperture spacing, mm Exilazooecia width, mm Acanthostyle diameter, mm Wall thickness in exozone, mm Nikiforovella sp. Aperture width, mm Metazooecia width, mm

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Saffordotaxis spinigerus sp. nov. Branch width, mm Exozone width, mm Endozone width, mm Aperture width, mm Aperture spacing along branch, mm Aperture spacing diagonally, mm Aktinotostyle diameter, mm Autozooecial budding angle, mm

N 20 20 20 40 40 40 40 13

X 0.86 0.30 0.27 0.09 0.51 0.29 0.05 27.3

SD 0.086 0.045 0.057 0.012 0.048 0.033 0.009 5.089

CV 9.94 15.22 21.15 12.75 9.50 11.32 18.05 18.64

MIN 0.70 0.22 0.15 0.07 0.40 0.23 0.04 21.0

MAX 1.00 0.41 0.40 0.11 0.60 0.36 0.07 37.0

N 19 19 19 25 25 25 30

X 0.94 0.22 0.50 0.05 0.34 0.22 0.03

SD 0.157 0.035 0.154 0.007 0.036 0.025 0.009

CV 16.72 16.16 30.70 13.76 10.64 11.45 36.80

MIN 0.70 0.14 0.27 0.04 0.30 0.17 0.01

MAX 1.35 0.28 0.91 0.07 0.40 0.26 0.04

N 14 15 30 30 30 30 30 30 30 30 10 10 7 15

X 0.44 0.25 0.41 1.15 0.75 1.49 0.12 0.29 0.27 0.16 5.5 0.09 0.61 0.057

SD 0.071 0.070 0.108 0.238 0.135 0.262 0.015 0.017 0.020 0.012 1.080 0.012 0.043 0.011

CV 16.26 28.69 26.15 20.70 18.03 17.57 13.18 5.74 7.39 7.69 19.64 13.36 7.13 18.74

MIN 0.36 0.15 0.23 0.78 0.50 1.00 0.09 0.26 0.23 0.14 4.0 0.08 0.55 0.045

MAX 0.62 0.40 0.60 1.73 1.00 2.00 0.15 0.33 0.31 0.18 7.0 0.11 0.68 0.075

N 20 20 20 20 20 20 20 13 6 20 9

X 0.27 0.15 0.34 0.88 0.59 1.04 0.09 0.25 0.21 0.12 4.2

SD 0.031 0.015 0.066 0.049 0.048 0.060 0.009 0.017 0.024 0.010 0.441

CV 11.61 9.95 19.39 5.62 8.18 5.81 10.44 6.66 11.85 8.24 10.44

MIN 0.23 0.12 0.22 0.78 0.50 0.94 0.08 0.23 0.16 0.10 4.0

MAX 0.34 0.17 0.50 0.95 0.70 1.15 0.11 0.28 0.23 0.14 5.0

Paranicklesopora ornaisa sp. nov. Branch width, mm Exozone width, mm Endozone width, mm Aperture width, mm Aperture spacing along branch, mm Aperture spacing diagonally, mm Acanthostyle diameter, mm Spinofenestella nodosa sp. nov. Branch width, mm Dissepiment width, mm Fenestrule width, mm Fenestrule length, mm Distance between branch centres, mm Distance between dissepiment centres, mm Aperture width, mm Aperture spacing along branch, mm Aperture spacing diagonally, mm Maximal chamber width, mm Apertures per fenestrule Keel node diameter, mm Keel node spacing, mm Node diameter, reverse side, mm Rectifenestella rudis (Ulrich, 1890), Branch width, mm Dissepiment width, mm Fenestrule width, mm Fenestrule length, mm Distance between branch centres, mm Distance between dissepiment centres, mm Aperture width, mm Aperture spacing along branch, mm Aperture spacing diagonally, mm Maximal chamber width, mm Apertures per fenestrule

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