Cyrtinoides Yudina and Rzhonsnitskaya, 1985, an aberrant Middle Devonian ambocoeliid brachiopod genus from China

Abstract

Here we redescribe and reillustrate specimens of an ambocoeliid brachiopod previously described as Echinocoelia guangsiensisSun, 1992 from the late Eifelian–earliest Givetian Mingtang Formation of the Liujing section in Guangxi Autonomous Region. The internal structure of the species, and especially the presence of a spondylium with tichorhinum in the ventral valve indicates that the species represents the aberrant genus CyrtinoidesYudina and Rzhonsnitskaya, 1985. It seems probable that the anterior part of the tichorhinum in Cyrtinoides accommodated the diductor attachments. Geographic distribution of Cyrtinoides is restricted to the Northern Hemisphere and shows a disjunct pattern. This genus has not hitherto been identified from China.