Eschrichtius akishimaensis, described in 2017, is one of two species, with the modern day gray whale, of the genus Eschrichtius, and is the first and only fossil species of the genus, dating to around 1.77–1.95 million years ago (mya) in the Early Pleistocene.
The bones were first found in 1961 by a father and son, Masato and Yoshio Tajima, in a riverbed in Akishima, Tokyo, lending it a nickname the Akishima whale, and put into storage at the National Museum of Nature and Science until it was transferred to Gunma Museum of Natural History to be studied.
The skeleton consists of a skull, neck vertebrae, thoracic vertebrae, lumbar vertebrae, tail vertebrae, chevrons, ribs, and arm bones, and has a total length of about 12 metres (39 ft). The discovery has generated local enthusiasm in the city, having both a Kujira matsuri (whale festival) and a Kujira Park (Whale Park) in its honor, and plans for a life-size replica skeleton in a new educational facility to open March 2020.
