Two New Materials of Whale Remains from the Holocene (Quaternary) of Osaka, Japan: Filling the Age of Lacking Reports on Holocene Baleen Whales from Japan

The book “Animal History of Japan” published in 1944 emphasized that “marine mammal study, especially on remains, has not yet begun.” At that time, there were not enough baleen whale remains. More remains were discovered from the 1960s. Since 2017, we have worked on baleen whale fauna reconstruction in the Holocene and Pleistocene of Osaka, Japan. We hereby summarize the reported Holocene baleen whales from Japan and report the finding of two additional baleen whale remains. In total, 13 Holocene baleen whale remains with morphological descriptions have been reported from Japan, with half of them being from Osaka. Comparison between the modern stranding records and baleen whale remains from Osaka indicates that the abundance of Balaenoptera physalus is a common phenomenon. However, the remains of Eubalaena sp. represents the differences between the past and the modern records, suggesting that the population of the right whale was larger during pre-historic times.