ammonites
Uncinunellina hayasakai Yanagida and Nishikawa 1984 (lamp shell)

Rhynchonellata - Rhynchonellida - Wellerellidae

Full reference: J. Yanagida and I. Nishikawa. 1984. Early Permian brachiopods from the Kawai Limestone, Hiroshima Prefecture, southwest Japan. Memoirs of the Faculty of Science, Kyushu University, Series D, Geology 25(2):159-197

Belongs to Uncinunellina according to J. Yanagida and I. Nishikawa 1984

Sister taxa: Uncinunellina amor, Uncinunellina exilis, Uncinunellina jabiensis, Uncinunellina mitigata, Uncinunellina mongolica, Uncinunellina multiplicata, Uncinunellina piqiangensis, Uncinunellina postera, Uncinunellina pulchra, Uncinunellina rotunda, Uncinunellina sangzhiensis, Uncinunellina shikokuensis, Uncinunellina siculus, Uncinunellina tenuis, Uncinunellina timorensis

Type specimen: GK-D 31644, a shell (Conjoined shell). Its type locality is Kogoro K-2, Hiroshima Prefecture, which is in a Sakmarian carbonate limestone in the Kawai Formation of Japan.

Ecology: stationary epifaunal suspension feeder

Average measurements (in mm): shell 11.7 x 14.4