Late Albian ammonoids from the Goshoura Group in the Tateishibana area, Shishijima, Kyushu, Japan

Abstract

Fourteen species of late Albian ammonoids, including a newly described species [Desmoceras (Pseudouhligella) trigonum sp. nov.], are reported from the Hokahira Member of the Enokuchi Formation, Goshoura Group in the Tateishibana area of Shishijima in Kagoshima, Kyushu, Japan. This ammonoid fauna resembles the late Albian ammonoid fauna of the Tethyan biotic realm as it includes genera such as Desmoceras (Desmoceras), Cantabrigites, Mortoniceras, Anisoceras, Hamites, Hemiptychoceras, Pseudhelicoceras, Lechites, Scaphites and Worthoceras, while it also includes species endemic to the Northwest Pacific region, such as D. (Pseudouhligella) shikokuense and D. (P.) trigonum sp. nov. The post-Albian early Cenomanian ammonoid fauna of the Northwest Pacific region is distinct from that of the Tethyan biotic realm and is characterized by many endemic species and remnants of the late Albian and their descendants. A cooling event may have occurred near the Albian–Cenomanian boundary that separated the faunas of the Tethys and North Pacific regions, and the late Albian ammonoids reported herein probably represent a fauna from just before that event occurred.

ZooBank registration: urn:lsid:zoobank.org:pub:7A331E27-05A3-4308-8F51-7AB704DDB6DA