Oceanithyris Bitner & Zezina

Bitner, Maria Aleksandra, Melnik, Vjacheslav P. & Zezina, Olga N., 2013, New paedomorphic brachiopods from the abyssal zone of the north-eastern Pacific Ocean, Zootaxa 3613 (3), pp. 281-288 : 283

Genus Oceanithyris Bitner & Zezina gen. nov.

Type species. Oceanithyris juveniformis Bitner & Zezina gen. et sp. nov.

Diagnosis. Small terebratulide, biconvex, shell surface with numerous wrinkled growth lines; foramen large, deltidial plates minute, triangular, disjunct, pedicle collar absent; teeth hooked, without dental plates; inner socket ridges high and anteriorly divergent; no cardinal process; lophophore trocholophous, with no brachial skeleton.

Etymology. Referring to the oceanic occurrence.

Remarks. Very few diagnostic characters can be seen, but the Family Dyscoliidae is the only one among short-looped brachiopods with representatives having a trocholophous lophophore in adults. Additionally, our specimens have very delicate striae in the posterior part; such striae are common in all dyscoliids known today, and this led us to attribute Oceanithyris juveniformis , with some doubts, to the Dyscoliidae .