How to translate text using browser tools
5 April 2023 The New Brittle-Star Species Stegophiura takaisoensis (Echinodermata, Ophiuroidea) from the Pliocene of Ibaraki Prefecture, Central Japan
Yoshiaki Ishida, Michio Tagiri, Taichi Kato, Shoji Tsunoda, Yasuhisa Nakajima, Ben Thuy, Lea D. Numberger-Thuy, Toshihiko Fujita
Author Affiliations +
Abstract

We describe three well-preserved, articulated brittle stars from the Pliocene Hatsuzaki Formation, Hitachi Group of Ibaraki, central Japan, as a new species, Stegophiura takaisoensis. It differs from its congeners in having dorsal arm plates with a high ridge and large swollen disk scales. The only other previously described extinct species unambiguously assigned to Stegophiura is S. miyazakii from the Upper Cretaceous of Japan. The new species from the Pliocene significantly adds to the fossil record of the genus, representing the second extinct species known to date and filling part of the fossil record gap between the Upper Cretaceous and the Recent representatives. The specimens have the disk and arms in intact live position, without any signs of transportation before buried. We assume that they were buried alive in their original deep shelf to upper slope habitat by rapid channel fills.

Yoshiaki Ishida, Michio Tagiri, Taichi Kato, Shoji Tsunoda, Yasuhisa Nakajima, Ben Thuy, Lea D. Numberger-Thuy, and Toshihiko Fujita "The New Brittle-Star Species Stegophiura takaisoensis (Echinodermata, Ophiuroidea) from the Pliocene of Ibaraki Prefecture, Central Japan," Paleontological Research 28(1), 82-96, (5 April 2023). https://doi.org/10.2517/PR220028
Received: 13 October 2022; Accepted: 23 January 2023; Published: 5 April 2023
KEYWORDS
Hatsuzaki Formation
Hitachi Group
Ophiopyrgidae
paleoenvironment
taphonomy
taxonomy
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top