TAXOCRINUS sp. (CRINOIDEA, FLEXIBILIA)
IN THE MIDDLE DEVONIAN OF MORAVIA
(CZECH REPUBLIC)

(Pl. VIII)
originally published in Folia Musei Rerum naturalium Bohemiae occidentalis, Geologica
vol. 38, pp. 16-19. Plzen.1993.

Rudolf J. Prokop - Vaclav Petr



Key words: Crinoidea, Flexibilia, Middle Devonian, Moravia, Czech Republic, bioclastic limestones, Taxocrinus.

Abstract: A specimen of flexible crinoid Taxocrinus sp. is described from the Middle Devonian (near the boundary Eifelian - Givetian) "Coral Red Beds" of the so-called "Ruzickuv lom" quarry near Celechovice, Moravia.


INTRODUCTION

The crinoid fauna from the Middle Devonian limestones of Moravia found at quarries near ?elechovice is relatively common, however poorly known, and needs a revision. Only several reports and very brief descriptions were given by previous authors. The first was those of Smycka (1895, p. 7) who reported from Celechovice two crinoid species: Cyathocrinites rugosus Miller and Cyathocrinus (?) ellipticus Phill. Further, Remes (1907, p. 95) reported from quarries near Celechovice three species: Synbathocrinus n. sp. (calyx, without description), Taxocrinus sp. ind. (part of arm, without description), Cupressocrinus sp. ind. (part of stem) and other unidentified fragments. First illustrations with short descriptions gave also Remes (1929, p. 242): Symbathocrinus celechovicensis sp. n. (calyx on Pl. I, fig. 3a, b) and Coccocrinus moravicus sp. n. (calyx on Pl. I, fig. 2). The latter author also reported (1929, p. 243, from the same quarries and without description): Eucalyptocrinus sp. (brachial plate ), Hexacrinus sp. (columnals), Taxocrinus sp. (brachials), Cupressocrinus sp. (brachial plate and columnals), Gasterocoma sp. (columnals), ?Mycocrinus sp. (part of radial circlet), and ?Cyathocrinus sp. (axillary plate). Finally, Boucek (1931) described Cupressocrinus crassus Goldf., var., after beautifully preserved crown, without calyx and proximal parts of arms. Complete crown was obtained by F. Ficner from the same locality. The latter specimen was described and figured by Remes (1939) as Cupressocrinus crassus Goldf., var. celechovicensis (We are reporting herein all genera and species in their original designations made by previous authors). The specimen of Boucek (discovered by P. Altar) was deposited in collections of the Faculty of Science, Charles University, and is now lost. Undescribed but beautiful Ficner's findings of crinoids from washings of weathered layers (Celechovice) are housed in collections of the Czech Geological Survey, Praha.

Possibly the most attractive specimen of a flexible crinoid so far known in the Palaeozoic of the Czech Republic comes from the Middle Devonian "Coral Red Beds" at "Ruzickuv quarry" near Celechovice. It was found in 1971 by P. Lukes and is described herein as Taxocrinus sp. Its stratigraphical position is uncertain because of lack of conodonts. Lowermost Givetian age is most probable (Chlupac, personal communication), but the uppermost Eifelian age cannot be completely excluded from calculation.

The authors are indebted to Prof. Ivo Chlupac for his valuable comments on the stratigraphical position of the discussed specimen and especially to Pavel Lukes for bringing his beautiful crinoid to their attention.



SYSTEMATIC PART


Class Crinoidea Miller, 1821
Subclass Flexibilia Zittel, 1895
Order Taxocrinida Springer, 1913
Family Taxocrinidae Angelin, 1878

Taxocrinus PHILLIPS in MORRIS, 1843

Type species: Taxocrinus macrodactylus (PHILLIPS, 1841), Upper Devonian, England.


Taxocrinus sp.
(Pl. VIII)

Holotype: Almost complete crown with stem 'in situ', deposited in collections of Pavel Lukes (plastotype is deposited in National Museum, Praha, under inv. n. L 30522), figured herein on Pl. VIII.

Type horizon: Middle Devonian, Eifelian - Givetian boundary strata (most probably lowermost Givetian).

Type locality: "Ruzickuv quarry" near Celechovice.

Material: holotype only.

Description: Crown in about anterior view, displaying A and E rays, while B ray is poorly preserved. Crown expands for about 75% of its height, thereafter contracting rapidly. Very low IBB are distinctly visible in the side view. Height of IBB forms about 25% of the height of BB. The BB are about as high as RR and the ratio height:width of both BB and RR is about 4:5. Each radial is markedly higher than the adjacent PBr1. Arms broad at base, reduced at each branching, forming a pyriform crown. Each observable ray terminates with a series of quadribrachials which are turned inward around the invisible sac-like tegmen. The ratio height:width in PBrBr is about 3:7. In the preserved rays, there are 3 PBrBr, 3 SBrBr, and 5, 8 and more TBrBr. Number of QBrBr is difficult to determine because the arms are very incomplete in their distal portions. All brachials are low and wide. Both the articular facets of all brachial plates (except the axillaries) and the radial facets of RR form obviously broad U-shaped median embayment with rounded corners (axillaries bear a doubble-U-shaped embayment). There are no observable interbrachials present and no plates of the crown showing any sort of ornamentation. Cylindrical stem is typically xenomorphic (see Moore, Jeffords & Miller 1968), with symplectial type of columnal articulation. Proxistele is short, formed of young, very thin columnals, while in longer mesistele region the columnals become thicker, alternating with younger thin ones. Long dististele i s represented by columnals which become uniform, with their height:width ratio attaining almost 1:2.

Dimensions of the holotype (in mm): Height of crown about 43; maximal width of crown about 40; width of proximal part of IBB circlet (and of proximal columnal too) 5; height of visible part of IBB in side view reaches 0.9; height of A radial 4; width of A radial 6; height of AE basal 3; width of AE basal about 5.5; maximal width of 2PBr and 3PBr in A ray 7; height of PBrBr in A ray about 3; width of PBrBr in A ray about 7; width of SBrBr generally 5 to 5.5; width of TBrBr generally 2.5; length of pr eserved part of stem 48; minimal height of columnals (in proxistele) 0.25; maximal height of columnals (in dististele) 1.5.

Remarks: Because of lack of the posterior side in this unique specimen, we cannot make any taxonomic conclusions about species assignment. We believe, however, that the Moravian species is a new one but only future findings can throw light on this problem for support or rejection of our present speculation. A very poor, problematic fragment of the cup of Taxocrinus sp. has been recently (Gluchowski, 1993, p. 46, Fig. 7 K-L) reported from the Polish Late Frasnian but it is younger and if it is really a Taxocrinus, it does not seem to be similar to the Moravian species. In the Czech Republic the Moravian species Taxocrinus sp. represents only the second so far known example of a taxocrinid crinoid coming from the Devonian. The first one belongs to the species Eutaxocrinus capella Prokop et Petr, 1987 which is reported from older rocks: Lower Devonian, Zlichovian (Lower Emsian) of Bohemia. Both are described only after one specimen.



References

BOUCEK, B. (1931): Zprava o novem zajimavem nalezu rodu Cupressocrinus GOLDF. v celechovskem devonu. - Cas. Vlasten. Spol. mus. (Olomouc), 44(3/4): 1-2. Olomouc.

BUCKLAND, W. (1837): Geology and Mineralogy Considered with Reference to Natural Theology. Vol. I: 618 pp. In: The Bridgewater Treatises on the Power Wisdom and Goodness of God as Manifested in the Creation, Treatise VI,, William Pickering. London.

GLUCHOWSKI, E. (1993): Crinoid assemblages in the Polish Givetian and Frasnian. - Acta Palaeont. Pol., 38(1/2): 35-92. Warszawa.

MOORE, R. C. (1978): Flexibilia. In: R. C. Moore & C. Teichert (Eds.): Treatise on Invertebrate Paleontology, Part T, Echinodermata 2, 2, T759-T812. The Geological Society of America, Boulder, Colorado, and the University of Kansas, Lawrence, Kansas.

MOORE, R. C. - JEFFORDS, R. M. - MILLER, T. H. (1968): Morphological features of crinoid columns. - Univ. Kansas Paleont. Contrib., 8, 45, 30 pp. Lawrence.

PROKOP, R. J. - PETR, V. (1987): Eutaxocrinus capella sp. n. (Crinoidea, Flexibilia) from the Bohemian Lower Devonian (Zlichovian). - Cas. Mineral. Geol., 32(2): 165-167. Praha.

REMES, M. (1907): Predbezna zprava o nekterych novych a vzacnejsich zkamenelinach celechovskeho devonu. - Vest. Klubu prirodoved. (Prostejov), 9 (for 1906): 95-96. Prostejov.

REMES, M. (1929): Paleontologicka studie z celechovickeho devonu. cast III: Prispevky k poznani jeho fauny. - Vest. Stat. geol. Ust., 5(2/3): 240-247. Praha.

REMES, M. (1939): Nektere vzacne nalezy v celechovskem devonu. - Cas. Vlasten. Spol. mus. (Olomouc), 52(2):156-160. Olomouc.

SMYCKA, F. (1895): Devonsti trilobiti u Celechovic na Morave. - Rozpr. Ces. Akad. Vedy Slovesn. Umeni, T?. II, 4(24): 1-14. Praha.

SPRINGER, F. (1920): The Crinoidea Flexibilia. - Smithsonian Inst. Publ., 2501, 486 pp. Washington, D. C.


Explanation to the plate



Pl. VIII

Taxocrinus sp. - almost complete crown with stem 'in situ', (photograph from collections of Pavel Lukes) - plastotype is deposited in the National Museum, Praha, inv. n. L 30522. Middle Devonian, Eifelian - Givetian boundary strata (probably lowermost Givetian), "RSzickuv quarry" near Celechovice, Moravia. x 1.5.


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