Translator Disclaimer
1 April 2016 The Last Surviving Ammonoid at the end of the Cretaceous in the North Pacific Region
Author Affiliations +
Abstract

This paper describes the first record of the heteromorph ammonoid Diplomoceras cylindraceum from the uppermost Maastrichtian Kawaruppu Formation of the Nemuro Group, southeastern Hokkaido, Japan. D. cylindraceum was found in a siltstone 15 m below the Cretaceous/Paleogene (K/Pg) boundary. The stratigraphical level of the fossil is estimated to be ∼66.8 Ma, based on the time scale for the geomagnetical polarity and the K/Pg boundary. D. cylindraceum, therefore, was living at least ∼0.8 m.y. before the K/Pg boundary event in the north Pacific region.

© by the Palaeontological Society of Japan
Ken'ichi Kurihara, Manabu Kano, Hiroshi Sawamura, and Yoshio Sato "The Last Surviving Ammonoid at the end of the Cretaceous in the North Pacific Region," Paleontological Research 20(2), 116-120, (1 April 2016). https://doi.org/10.2517/2015PR027
Received: 7 August 2015; Accepted: 1 September 2015; Published: 1 April 2016
JOURNAL ARTICLE
5 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top