Borhyaenids

Borhyaenids are a group of extinct mammals that lived during the Paleogene period, from the Paleocene to the Oligocene epochs, approximately 66 to 23 million years ago. They are known from fossils found in North America, Europe, and Asia. Borhyaenids are characterized by their small to medium-sized body size, ranging from 1 to 3 meters in length, and their distinctive skull morphology, which includes a long, narrow snout and large, sharp teeth.

The earliest known borhyaenids are from the early Paleocene of North America, and they diversified rapidly during the Eocene, with numerous species appearing in Europe and Asia. Borhyaenids were likely carnivorous, and their teeth and skull structure suggest they may have fed on small to medium-sized prey, such as mammals, reptiles, and possibly even insects.

Borhyaenids are often considered to be a sister group to the modern-day carnivorans, such as dogs, cats, and bears. This relationship is supported by several anatomical features, including the structure of their teeth and the arrangement of their bones. However, the exact evolutionary relationships among borhyaenids and other carnivorans are still a topic of ongoing research.

Borhyaenids went extinct at the end of the Oligocene, around 23 million years ago. The cause of their extinction is not well understood, but it may have been related to changes in climate or the evolution of new predators. Despite their relatively short evolutionary history, borhyaenids played an important role in the evolution of modern-day carnivorans, and their fossils provide valuable insights into the early diversification of these mammals.