2025/01/01 by Akira Ota, Tomohiro Nishimura, Yoshitsugu Kobayashi +1 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Plant Diversity and Evolution #Plant and Fungal Species Descriptions #Plant and animal studies
paper · pdf · doi:10.2517/prpsj.240013
openalex publication_date 2025/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Herein, we describe Callorhinchus orientalis sp. nov., an extinct callorhinchid chondrichthyan species found in the lower Maastrichtian deposits of the Hakobuchi Formation in Hobetsu, Hokkaido, northern Japan. This species is the first record of the genus Callorhinchus from the northern Pacific region, filling the biogeographical gap and implying survival beyond the Cretaceous/Paleogene extinction event because of the broad distribution of the genus. A comparison of Maastrichtian Callorhinchus species, including C. orientalis sp. nov., and Danian species indicates a potential period of temporal dwarfing within the genus across this extinction event.