Overlooked biodiversity of brittle stars from the Upper Pleistocene of Japan: descriptions of fossil ossicle assemblage in Indo-West Pacific

Disarticulated fossil ossicles of brittle stars from the Upper Pleistocene Yokosuka Formation, Yokosuka, Kanagawa Prefecture, central Japan, are described. The ossicles of lateral arm plates and vertebrae are assigned to Gorgonocephalidae, Ophiocomidae, Ophiosphalmidae, <i>Ophiopholis, Ophiothrix, Ophiarachnella, Stegophiura sladeni, Ophiuroglypha kinbergi</i> and <i>Ophiozonella longispina</i>, on the basis of external morphology. This is the first faunal record mainly based on disarticulated fossil lateral arm plates of brittle stars from the Indo-Pacific region.

本研究记述了产自日本中部神奈川县横须贺市更新世上层横须贺组的分散保存海蛇尾（brittle stars）化石骨片（ossicles）。基于外部形态特征，将其中侧腕板与椎骨骨片归入筐蛇尾科（Gorgonocephalidae）、阳遂足科（Ophiocomidae）、隐足蛇尾科（Ophiosphalmidae），以及*Ophiopholis*、*Ophiothrix*、*Ophiarachnella*、*Stegophiura sladeni*、*Ophiuroglypha kinbergi*与*Ophiozonella longispina*等属种。本研究为印度洋-太平洋区域首次以海蛇尾分散保存的化石侧腕板为主要依据的动物群记录。