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.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 20 • No. 2