Callorhinchus orientalis

Callorhinchus orientalis Temporal range: Maastrichtian PreꞒ Ꞓ O S D C P T J K Pg N
Type specimen
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Holocephali
Order:	Chimaeriformes
Family:	Callorhinchidae
Genus:	Callorhinchus
Species:	†C. orientalis
Binomial name
†Callorhinchus orientalis Ota et. al., 2025

Callorhinchus orientalis is an extinct species of plough-nosed chimaeras (also called elephantfish) in the genus Callorhinchus that lived during the Maastrichtian stage of the Cretaceous period.

Distribution

Callorhinchus orientalis is known from the Hakobuchi Formation of Hokkaido, Japan. ^[1] Members of Callorhinchus had two pairs of platelike teeth in the upper jaw, with one pair in the lower jaw.

On April 9, 2025, a fossilized tooth, originally found in Hobetsu in 2013, was identified as being the first known case in the North Pacific of Callorhinchus orientalis. The upper jaw tooth, approximately 3.2 centimeters long and 1.5 cm wide, was found by Sapporo researchers in a stratum dating back roughly 72 million years. The fossilized tooth featured a pawlike bulge, a characteristic previously unseen in previously known extinct species. The discovery was announced by the Mukawa Town Hobetsu Museum and the Hokkaido University Museum. ^[2]

References

1. Ota, Akira; Nishimura, Tomohiro; Kobayashi, Yoshitsugu; Moriki, Kazunori (2025). "Callorhinchus orientalis sp. nov., a new callorhinchid from the Upper Cretaceous Hakobuchi Formation, Yezo Group, Hokkaido, Japan". Paleontological Research. 29 (0): 54–63. doi:10.2517/prpsj.240013. ISSN   1342-8144 . Retrieved 11 April 2025.
2. "Fish fossil found in Hokkaido named new species". The Mainichi. April 11, 2025.