CARPOCRINUS ORNATUS (ANGELIN, 1878) (CRINOIDEA, CAMERATA) FROM THE SILURIAN OF THE BARRANDIAN AREA 
(CZECH REPUBLIC)
 

Originally published in: Časopis Národního muzea, Řada přírodovědná, 168 (1-4): 135-136. Praha 1999

Rudolf J. Prokop1 - Václav Petr2


1 Department of Palaeontology, Museum of Natural History, National Museum, 115 79 Praha 1, Czech Republic
2 Zoological Library, Faculty of Sciences, Charles University, 128 44 Praha 2, Czech Republic

During current research of the crinoid assemblages from the tuffites and tuffitic limestones of the Kopanina Formation (Ludlow), a few calyces and crowns of carpocrinid crinoids have been discovered in the quarries "Amerika" near Karlštejn. These remains belong most probably to the species Carpocrinus ornatus (Angelin, 1878) recorded previously from the Silurian of Gotland (Sweden).


Subclass   Camerata WACHSMUTH et SPRINGER, 1885
Order       Monobathrida MOORE et LAUDON, 1943
Family      Carpocrinidae DeKONINCK et LeHON, 1854

Carpocrinus MÜLLER, 1840

Type species: Actinocrinites simplex PHILLIPS in MURCHISON, 1839, Silurian (Wenlock), England


Carpocrinus ornatus (ANGELIN, 1878)
 (Text-fig. 1)

Material: One almost complete crown (cat. No. L 8991) and one calyx (cat. No. L 33134); both specimens isolated from the tuffitic limestone. They are deposited in the repository of the Palaeontological Department of the National museum, Praha.

Remarks: The remains of Carpocrinus ornatus (Angelin, 1878) found in the Czech Silurian (Barrandian area) correspond exactly with the specimens from the Silurian of Gotland. The calyx of the Czech specimens is built by thick calyx plates bearing bulbous central swellings of the external surface. BB are poorly preserved so that the description of their exact shape and number is impossible. As in the Gotland specimens, the first PBr is quadrangular, and the CD interray possesses a typical median series of anal plates. Fixed SBrBr are three, interprimibrachs about 12, merging into the tegmen. Tegmen is solid, orals and ambulacrals distinct and well-discernible. Free arms are not very complex, two in each ray, uniserial, with simple brachials. Proximal portion of the column is poorly preserved, cylindrical to slightly pentalobate in outline.


Dimensions  (in mm):  whole         height          max.           width
                                    height        of calyx       width          of calyx

 L 8991                           49              21              27                23
 L 33143                          -                24               -                 22


Occurence: Ludlow, Kopanina Formation, Kopanina Limestone, Encrinurus beaumonti Zone. "Amerika" quarries near Karlštejn.

Note: First report announcing the presence of the genus Carpocrinus in the Silurian of Bohemia is that published by Růžička and Bouška (1944). On their text-fig. 4a, the latter authors presented a nearly complete crinoid crown without stem and designated it as Carpocrinus sp.(near to the species C. simplex). The figured crown came from the same stratigraphic level and locality as the crinoid remains described here. The specimen has been originally housed in Bouška's private collection and at present it is probably lost.

Fig. 1: Carpocrinus ornatus (Angelin, 1878), specimen cat. No. L 8991. Tuffitic limestones of the Kopanina Formation (Encrinurus beaumonti Zone), "Amerika" quarries near Karlštejn. Barrandian, Czech Republic (Photo by R. J. Prokop).


REFERENCES

Angelin, N. P. (1878): Iconographia crinoideorum in stratis Sueciae Siluricis fossilium. - Samson et Wallin (Holmiae), 62 pp., 29 pls. Stockholm.

Růžička, R. - Bouška, J. (1944): Zkameněliny z českého siluru z lomu "Amerika" u Vel. Mořiny. – Věda přírodní, 22, 7: 189-193. (In Czech).

Ubaghs, G. (1978): Camerata. In: Treatise on Invertebrate Paleontology, (ed. R. C. Moore and C.Teichert), Part T, Echinodermata 2, Vol. 2: T462-66. Boulder, Colorado and Lawrence, Kansas.

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