Ancient Marine Predator Discovered in Japan, Lived 237 Million Years Ago

New Species of Hybodontiform Shark-Like Fish Unveiled

A research team from the National Museum of Nature and Science in Japan has identified a new species of ancient marine predator that roamed the seas approximately 237 million years ago. Named Parvodus ominechonensis, this creature belongs to a group of extinct shark-like fish called Hybodontiforms, which were prominent during the early stages of the dinosaur era.

Discovery and Description

Fossil remains of Parvodus ominechonensis were discovered in the non-marine Momonoki Formation in Yamaguchi Prefecture, Japan. These isolated teeth provide valuable insights into the anatomy and characteristics of this species.

Parvodus ominechonensis and its Hybodontiform lineage shared striking similarities with modern sharks. They are believed to have shared a common ancestor.

Hybodontiform Lineage

Hybodontiforms thrived during the Devonian, Carboniferous, Permian, Triassic, Jurassic, and Cretaceous periods before eventually going extinct. These fish represented a close evolutionary link between modern sharks and rays (Neoselachii).

Global Distribution and Speciation

Fossils of Hybodontiforms have been unearthed in various locations around the world, including the United States, China, and South America. The discovery of Parvodus ominechonensis in Japan underscores the wide-ranging distribution and diversity of this lineage throughout its existence.

Evolutionary Origins

The study, published in the Journal of Vertebrate Paleontology, suggests that Parvodus originated in freshwater environments in what is now southern China, when it was part of an ancient supercontinent. The genus likely emerged after a mass extinction event at the end of the Permian period and diversified in East Asia during the Triassic before spreading globally.

Summary

The identification of Parvodus ominechonensis offers valuable insights into the diversity and evolution of Hybodontiform fish. This discovery extends our understanding of the ancient marine ecosystem during the early Mesozoic era.