ISSN 0031�0301, Paleontological Journal, 2013, Vol. 47, No. 6, pp. 581–587. © Pleiades Publishing, Ltd., 2013. Original Russian Text © E.V. Sokiran, 2013, published in Paleontologicheskii Zhurnal, 2013, No. 6, pp. 24–28. 581 1 Spiriferide brachiopods of the genus Cyrtospirifer are widespread and abundant in the Upper Devonian deposits in Europe, Middle East and North America. However, a number of widely recognized species of this genus, mostly established in the 19th and early 20th century remain poorly understood or misunder� stood because of insufficient knowledge of the type material, absence of documentation of their precise stratigraphic origin, and insufficient information on the morphology available from the original publica� tions (Sartenaer 1999; Ma and Day 1999). In particu� lar, such a brachiopods as Cyrtospirifer disjunctus (Sowerby, 1840) is widespread in the Frasnian deposits of the East European Platform and even used as the index species of the Cyrtospirifer disjunctus—Stenom� etoporhynchus pavlovi Biozone (Rzhonsnitskaya, 2000). The type material of Spirifer disjunctus comes from the Devonian deposits of the outskirts of Barnstaple and Petherwin (Cornwall, United Kingdom), from which has been described by J. Sowerby (Sowerby in Sedgwick and Murchison, 1840). E. Verneuil was the first who reported Spirifer disjunctus from the Late Devonian of central European Russia (Verneuil in Murchison et al., 1845). Shells described by E. Verneuil were sampled in outskirts of Petino villages (Don river basin) and there is no doubt that they came from the rocks subsequently assigned to the Upper Semiluki subhorizon. In 1930 D.V. Nalivkin placed Spirifer disjunctus described by Verneuil from central European Russia to 1 The article was translated by the authors. Cyrtospirifer. No attempts were made, however, to compare Russian shells directly with the actual types from Britain and they are completely missing in the latest publications (e.g., Nalivkin 1947; Ljaschenko 1959). Identification of British and Russian shells were a consequence of their lack of full study, because of the very poor state of preservation of British shells described and illustrated by J. Sowerby (Sedgwick and Murchison, 1840, pl. 53, fig. 8; pl. 54, figs. 12, 13) and later by J. Phillips (1841, pl. 29, figs. 128f–128h, 129; pl. 30, fig. 129), there was no reliable data on the exter� nal and internal morphology of representatives by this species. Therefore, the main features of S. disjunctus and later Cyrtospirifer disjunctus in understanding of E. Verneuil (in Murchison et al., 1845), F.N. Cherny� shev (1887), S.V. Obruchev (1915), D.V. Nalivkin (1930, 1947) and A.I. Ljaschenko (1959) was sub� quadrate shells and relatively low interarea with nearly parallel edges. However the typical samples from the Petherwin Formation differ from the Russian species not only stratigraphically but also morphologically. According to L.E. Popov and M. Basset (personal communication) the originals of Spirifer disjunctus from the J. Sowerby collection were lost. Currently, the collection includes a single specimen identified by J. Sowerby; however, it is poorly preserved; its photo� graphs were kindly provided by L.E. Popov and M. Bassett (Pl. 7, fig. 2), as well as photographs Spiri� fer disjunctus from the collection of Phillips (Pl. 7, figs. 1, 3–6). There were at least three working quarry in South Petherwin is the main source of spiriferide shells in the Cyrtospirifer vjacheslavi, a New Cyrtospiriferid Species (Cyrtospiriferidae, Brachiopoda) from the Middle Frasnian of the East European Platform1 E. V. Sokiran All�Russia Research Institute of Oil and Geological Prospecting, Liteinyi pr. 39, St. Petersburg, 192104 Russia e�mail:
[email protected] Received July 21, 2011; in final form, February 1, 2013 Abstract—A new spiriferid brachiopod species, Cyrtospirifer vjacheslavi, from the Middle Frasnian of the East European Platform is described. These spiriferide shells from the Middle Frasnian of central Euro� pean Russia and Middle Timan assigned traditionally to Cyrtospirifer disjunctus for more then a century are not conspecific to British species and are here reassigned to Cyrtospirifer vjacheslavi sp. nov. Keywords: Brachiopoda, Spiriferida, new species, Devonian, Middle Frasnian, East European Platform, Russia DOI: 10.1134/S0031030113060099 582 PALEONTOLOGICAL JOURNAL Vol. 47 No. 6 2013 SOKIRAN area where J. Sowerby and J. Phillips collected Spirifer disjunctus. According to Steward (1981) a single lime� stone bed within the unit contains conodonts indicative of the Famennian upper Scaphignathus velifer to lower Polygnathus styriacus zones. Unfortunately currently poor preservation of shells of Spirifer disjunctus poses problems with the study of their internal structure and therefore their exact generic identification. In Russia the name Cyrtospirifer disjunctus is attrib� uted to the spiriferide shells spread widely in the deposits corresponding to the Semiluki Horizon. In fact these shells have an excellent preservations and are different in the morphology and age from British Spirifer disjunctus and they are regarded here as a sep� arate new species Cyrtospirifer vjacheslavi sp. nov. Shells of the new species considered in the present study come from two main sources: (1) the Semiluki Horizon of the Don River Basin in the Voronezh Region (also known in Russian geological literature as the “Central Devonian Field”); and (2) deposits cor� responding to the Kraipol Formation of Middle Timan. In the Central Devonian Field Cyrtospirifer vjacheslavi sp. nov. usually co�occurs with the brachi� opods Stenometoporhynchus pavlovi (Nalivkin, 1930), Nervostrofia gassanovae (Ljaschenko, 1959), Hypothy� ridina semilukiana Nallivkin, 1930, Pseudoatrypa uralica (Nalivkin, 1930), Cyrtina demarlii Bouchard, 1949, Anathyris helmersenii (Buch, 1840). According conodonts this level corresponds to the Polygnathus efimovae Zone. In Middle Timan Cyrtospirifer vjacheslavi sp. nov. occurs in the Kraipol Formation from the natural out� crops exposed in the Tsylma, Myla and Pizhma Pechorskaya river basins. Conodont assemblage reported by Kuzmin (2001) suggesting the Middle to Upper Po. asymmetricus Zone. The deposits of the upper part of the Kraipol Formation are tentatively assigned to the Ancyrognathus triangularis Zone (Kuzmin 2001). Associated brachiopod fauna from the Kraipol Formation includes such taxa as Stenom� etoporhynchus pavlovi (Nalivkin, 1930), ‘Atrypa’ koloschka Nalivkin, 1941, ‘Atrypa’ svinordi (Venyukov, 1886) Spinatrypa (Spinatrypa) semilukiana Ljas� chenko, 1959, Cyrtospirifer rudkinensis Ljacshenko, 1959, C. mylaensis Sokiran, 2006, C. tenticulum (Ver� neuil 1845), Cyrtina demarlii (Bouchard, 1949), Ilme� nia perlevis (Nalivkin, 1930), I. altovae Nalivkin, 1941, Anathyris svinordensis Nalivkin, 1941, Anathyris helmersenii (Buch, 1840). Order Spiriferida Waagen, 1883 Suborder Spiriferidina Waagen, 1883 S u p e r f a m i l y Cyrtospiriferoidea Termier et Termier, 1949 Family Cyrtospiriferidae Termier et Termier, 1949 Subfamily Cyrtospiriferinae Termier et Termier, 1949 Genus Cyrtospirifer Nalivkin in Frederiks, 1924 Cyrtospirifer vjacheslavi Sokiran, sp. nov. Plate 6, figs. 1–4 Spirifer disjunctus Sowerby: Murchison et al., 1845: p. 157, pl. 4: fig. 4; Chernyschev, 1884: pl. 2, fig. 7; Obrouchev, 1916, p. 46, pl. 2, figs. 1, 2. Spirifer Archiaci Murchison: Venyukov 1886, p. 66, pl. 3, fig. 2. Spirifer Verneuili Murchison: Venyukov 1886: p. 66, pl. 3, fig. 4. Cyrtospirifer disjunctus (Sowerby): Nalivkin 1947, p. 113, pl. 27, fig. 4; Ljaschenko 1959, p. 176, pl. 52, figs. 1–3. E t y m o l o g y. In honor of late Professor Vjacheslav G. Khalymbadzha. H o l o t y p e: CNIGR 2332/2858, complete shell, central regions of East European platform, right bank of the Don River, Semiluki village, Upper Devonian, Middle Frasnian, Upper Semilukian subhorizon. D e s c r i p t i o n (Fig. 1). The shells are medium� sized slightly ventribiconvex, subquadrate to trans� verse trapezoidal in outline with the maximum width at the hinge line, cardinal extremities are acute and alate. The anterior commissure is uniplicate. The ven� tral valve is strongly and evenly convex in lateral profile with a beak projecting strongly beyond the hinge line and curved dorsally. The lateral slopes are very slightly convex in the lateral profile, becoming concave mar� ginally in strongly alate specimens. The ventral inter� area is curved, strongly apsacline, with the outer mar� gins almost parallel to the hinge line, declining abruptly near cardinal extremities. The delthyrium is large, triangular, up to 5 mm high and varying from 3.1 to 6.7 mm in width in the largest specimens, covering up to half its height by the secondary shell deposits under the pedicle callist. The ventral sulcus is deep and narrow, originating at the umbo and terminated into a low, rounded tongue. The dorsal valve is moderately and evenly convex with a low and narrow median fold rounded in cross section and originating at the umbo. The lateral slopes are gently convex in transverse pro� file. The dorsal interarea is low, nearly orthocline. Radial ornament is costate with flattened ribs on flanks, bifurcating mainly in the ventral sulcus and dorsal fold. The number of ribs varies from 11 to 16 in E x p l a n a t i o n o f P l a t e 6 Figs. 1–4. Cyrtospirifer vjacheslavi sp. nov.; 1—CNIGR 2332/2858, holotype, complete shell, ventral valve (1a) (×1.5), dorsal valve (1b) (×1.5), posterior view (1c) (×1.5), lateral view (1d) (×1.5) of conjoined valves., East European Platform, Voronezh region, village of Semiluki, right bank of the Don River, Upper Devonian, Middle Frasnian, Upper Semilukian subhorizon. 2— CNIGR 2332/2858, complete shell, 2a—ventral valve (×1.5), dorsal valve (2b) (×1.5), posterior view (2c) (×1.5) of conjoined valves., Middle Timan, left bank of the Myla River, Upper Devonian, Middle Frasnian, Kraipol Formation. 3—CNIGR 1/13124, radial ornament in ventral sulcus showing pustules (×5), 4—CNIGR 2/13124, radial ornament and superimposed con� centric fila (×5), all Middle Timan, left bank of the Myla River, Upper Devonian, Middle Frasnian, Kraipol Formation. PALEONTOLOGICAL JOURNAL Vol. 47 No. 6 2013 CYRTOSPIRIFER VJACHESLAVI, A NEW CYRTOSPIRIFERID SPECIES 583 4 Plate 6 1a 1d 2a 1b 2e 2b 1c 2d 2c 3 584 PALEONTOLOGICAL JOURNAL Vol. 47 No. 6 2013 SOKIRAN the dorsal median fold and ventral sulcus, and from 17 to 27 on flanks of both valves. Most of the costae bifur� cate from the median rib and from a pair of ribs flank� ing the fold and sulcus. Superimposed radial capillae are very fine, about 50 per 5 mm, and usually poorly preserved. The surface of the ventral interarea is also covered with fine vertical capillae usually obscured by concentric ornament of strong, ridgelike, evenly spaced fila up to 27 per 5 mm. Fine pustules are (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) (n) (o) (p) (q) (r) (s) (t) (u) 5 mm Fig. 1. Cyrtospirifer vjacheslavi sp. nov.: a–x CNIGR 4/13124—transverse serial sections of the shell (×2), East European Platform, Voronezh region, Semiluki village, right bank of the Don River, Upper Devonian, Middle Frasnian, Upper Semilukian subhorizon. E x p l a n a t i o n o f P l a t e 7 Figs. 1–6. Spirifer disjunctus (Sowerby); 1—NHM BC 58481, latex cast of ventral internal mould (×1.5), 2—NHM Bb 350, internal mould of conjoined valves (×1.5), 2a—ventral and 2b—dorsal views, 3—NHM BC 58482: 3a—latex cast of ventral internal mould (×1.5), 3b—posterior view of ventral internal mould (×1.5), 4—NHM BC 58485, posterior view (×1.5), 5—NHM B43939/a, latex cast of ventral internal mould (×1.5), 6—NHM B43939/b; 6a—latex cast of ventral valve (×1.5), 6b—radial ornament in ventral valve (×4), United Kingdom, Cornwall, South Petherwin, Landlake quarry, Upper Devonian, Middle�Upper Famennian, Petherwin Formation. PALEONTOLOGICAL JOURNAL Vol. 47 No. 6 2013 CYRTOSPIRIFER VJACHESLAVI, A NEW CYRTOSPIRIFERID SPECIES 585 Plate 7 1 2a 3a 3b 2b 4 6а 5 6b 586 PALEONTOLOGICAL JOURNAL Vol. 47 No. 6 2013 SOKIRAN present, but poorly preserved in the most of observed shells. The ventral interior has a prominent pedicle callist, strong teeth and long, diverging, extrasinal dental plates with adminicules. The dorsal interior has a wide ctenophoridium clearly subdivided into two lateral parts, dorsolaterally directed crura, and a fine median ridge bisecting the adductor muscle field. The spiralia have up to 12 whorls. D i m e n s i o n s i n m m a n d r a t i o s: C o m p a r i s o n a n d r e m a r k s. Shells of Spirifer disjunctus deposited in the Natural History Museum, London revealled that they differ signifi� cantly from Cyrtospirifer vjacheslavi sp. nov. in spite of sometimes significant distortion of the British shells. Spirifer disjunctus has a broader triangular interarea and ribs bifurcations on flanks of both valves. The new species is morphologically similar to C. mylaensis Sokiran 2006, however, the latter is characterized by a more developed wide trapezoidal shell, a relatively high triangular ventral interarea, fewer ribs in the sul� cus and fold, which is extremely poorly developed, in the middle of which there is a slight depression. Lower Semilukian Cyrtospirifer rudkinensis Ljaschenko, 1959 differs in its larger shell, triangular ventral interarea, higher and coarser ribs. Some representatives of Cyrtospirifer schelonicus Nalivkin, 1941 from Lower Semilukian Subhorizon, which is rather variable, is similar to Cyrtospirifer vjacheslavi sp. nov. However C. schelonicus has a wide trapezoidal shell with a high triangular interarea and well�developed dorsal median fold. Cyrtospirifer vjacheslavi also has a distinct affinity to Early Frasnian Cyrtospirifer malaisi (Gosselet, 1894) from the Dinant Basin, which Sartenaer (1982) considered as the type species of the genus Subquadri� angulispirifer, however, Carter et al. (1994) regarded this genus as a junior synonym of Cyrtospirifer. Our shells differ from Cyrtospirifer malaisi in having a deeper sulcus and rounded lateral shell margins. Peetz (1901) proposed that Cyrtospirifer lonsdalii (Murchi� son 1840) is a synonym of Spirifer disjunctus (=Cyrtospirifer vjacheslavi sp. nov.), because it also has a narrow interarea with outer edges subparallel to the hinge line. In fact, a narrow interarea with parallel edges is observed in other species of the genus, such as Cyrtospirifer grabaui Paeckelmann (Paeckelmann, 1942, p. 111, pl. 4, figs. 1–3; Vandercammen, 1959, Specimen no. L W L/W T Hrvv Holotype 2332 29.20 37.30 0.78 16.6 4.0 2604 27.60 37.60 0.73 20.60 4.70 2603 30.90 37.90 0.81 23.50 2.0 2843 30.10 36.10 0.83 26.80 1.90 2611 29.70 36.90 0.80 28.40 3.00 2585 29.50 40.60 0.73 23.40 3.90 2614 25.20 34.80 0.72 20.70 3.10 2855 27.90 33.30 0.84 32.30 2.50 2614 26.70 35.0 0.76 20.50 2.90 2848 25.60 34.80 0.74 18.70 pl. 5, figs. 1–9); however, this species differs from C. vjacheslavi in the well�developed dorsal median fold and the winged shell shape. Perhaps, Cyrtospirifer lonsdalii (Murchison, 1840, pl. 2, figs. 1–2; Grabau, 1931, p. 213, pl. 27, figs. 1–6) from the Frasnian of Ferques is synonym Cyrtospirifer grabaui Paeckelmann (Paeckelmann, 1942, p. 111, pl. 4, figs. 1–3; Vander� cammen, 1959, pl. 5, figs. 1–9). R e m a r k s. Specimens of Spirifer disjunctus (Pl. 7, figs. 6a, 6b) show numerous rib bifurcations on flanks of both valves, whereas in Cyrtospirifer radial ribs are simple on flanks and bifurcating only in the ventral sulcus and dorsal fold. However, imperfect preservation of shells in the type locality makes very difficult to prove it without a general revision of the taxa assigned to the subfamily Cyrtospiriferinae, which is far beyond the scope of the present paper. O c c u r r e n c e. Upper Devonian, Middle Fras� nian, Upper Semiluki Subhorizon of the central regions of European Russia; Kraipol Formation of the Middle Timan. M a t e r i a l. Ten complete shells from D.V. Nalivkin’s collection (CNIGR no. 2858) and 109 specimens from M.M. Tolstichina collections (CNIGR no. 13020) all specimens come from the Upper Semiluki Subhorizon (villages of Petino, Semi� luki, Devitsa, and Ust’e). 118 complete shells and 49 disarticulated valves from F.N. Chernyshev collec� tions (CNIGR no. 1226) from the Kraipol Formation of the Tsylma, Myla, and Pizhma Pecherskaya rivers in Middle Timan. Abbreviations. L—length of shell, W—width of shell. L/W—the ratio of length to width of shell, T— thickness of shell, Hrvv—height of interarea of pedi� cle valve. The brachiopods described in this paper are housed at the CNIGR Museum in St. Petersburg. ACKNOWLEDGMENTS I am grateful to Dr. M. Basset and Dr. L.E. Popov (Department of Geology, National Museum of Wales, Cardiff, United Kingdom) for assistance in the study of British material and valuable advice in writing the article. National Museum of Wales provided fundidng for E.V. Sokiran during her visit to Cardiff in 2000. The study was supported by Silesian University at Sosnow� iec (Poland), the Polish State Committee for Scien� tific Research (KBN grant 3 P04D 040 22, headed by Dr. G. Racki). REFERENCES Carter, J.L., Johnson, J.G., Gourvennec, R., and Hou, H.F., A revised classification of the spiriferid brachio� pods, Ann. Carnegie Mus., 1994, vol. 63, pp. 327–374. Chernyshev, F.N., Materials to the study of the Devonian of Russia, Tr. Geol. Kom., 1884, vol. 1, no. 3, pp. 1–81. 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