Yesoensis refers to a species of extinct marine bivalve mollusks that lived during the Cretaceous period. These organisms are characterized by their distinctive shell shapes and were part of the diverse marine ecosystems of their time. Fossils of yesoensis have been found in various locations, providing insights into the ancient environments they inhabited. The name yesoensis is derived from the region of Yezo in Japan, where the first specimens were discovered. These bivalves played a role in the marine food web, serving as both filter feeders and prey for larger animals. Their fossils contribute to the understanding of evolutionary history and paleoenvironments.