A Miocene breeding ground of an extinct baleen whale (Cetacea: Mysticeti)

• Published in: PeerJ
• Main Author: Tsai, Cheng-Hsiu
• Other Authors: Japan Society for the Promotion of Science Postdoctoral Research Fellowship
• Format: Article in Journal/Newspaper
• Language: English
• Published: PeerJ 2017
• Subjects: baleen whale
• Online Access: http://dx.doi.org/10.7717/peerj.3711; https://peerj.com/articles/3711.pdf; https://peerj.com/articles/3711.xml; https://peerj.com/articles/3711.html

Locating breeding sites is definitely a key to understanding the ecological requirements and maintaining the sustainability of populations/species. Here I re-examined published specimens of an extinct baleen whale, Parietobalaena yamaokai , from the lower part of Itahashi Formation (16.1–15.6 Ma, Middle Miocene) in Shobara, Hiroshima, Japan. A critical and previously unnoticed feature, the open suture between the supraoccipital and exoccipital, in one specimen indicates the preservation of a very young individual–under six months old and even close to a new-born calf. Given the occurrence of a new-born whale and relatively abundant assemblage of Parietobalaena yamaokai , I propose a previously hidden and unknown breeding ground for the extinct baleen whale, P. yamaokai , in the Middle Miocene of Shobara (16.1–15.6 Ma), Hiroshima. Discovery of paleo-breeding sites of extinct populations/species should further help us to understand biological extinctions from a long-term perspective as conservation paleobiology aims to offer new insights into policy making for conserving endangered populations/species.