Leptathyris sp.

Mergl, Michal & Budil, Petr, 2019, Rhynchonelliform Brachiopods And Trilobites Of The ‘ Upper Dark Interval’ In The Koněprusy Area Devonian, Eifelian, Kačák Event; The Czech Republic, Fossil Imprint 75 (1), pp. 92-107 : 99

Leptathyris sp.

Pl. 2, Figs 11–13

M a t e r i a l. Two figured complete shells (PCZCU 2283, PCZCU 2284), one ventral valve (PCZCU 2282) and several unfigured mostly incomplete dorsal and ventral valves.

D e s c r i p t i o n. The shell is biconvex, thin-walled, rectimarginate, small, with a maximum width of 3.3 mm. The shell substance is impunctate. The dorsal valve is subcircular, with a short beak, lenticular in transverse and axial profiles, with evenly rounded margins. The ventral valve has similar convexity but has an erect posteriorly extended beak with low apsacline palintrope.

R e m a r k s. This species is the commonest brachiopod in the UDI. Three articulated specimens were observed, but their interior is unknown. Leptathyris gryphis SIEHL, 1962 from the Greifenstein Limestone (Eifelian) of Rhineland differs by the shallow sulcus in both valves. Leptathyris deino HAVLÍČEK, 1990 (in Havlíček and Kukal 1990) from the Suchomasty Limestone (Emsian) is similar in its rectimarginate commissure but is much larger than specimens observed in the UDI. In terms of shape and smooth outer surface, the shell is also similar to Leptathyris circula ( WALCOTT, 1884) , a common species from the Eifelian of Nevada ( Johnson 1966), but differs in its rectimarginate anterior commissure. Externally, the shell is similar to Eobiernatella BALIŃSKI, 1995 from the Givetian and Frasnian of Poland and Russia in its rectimarginate commissure and absence of a sulcus.

O c c u r r e n c e. UDI, sample TM 12.