1) Transitional fossil 
Parictis is the earliest genus of bear known. It was a very small and graceful ursid with a skull only 7 cm long. Parictis first appeared in North America in the Late Eocene (ca. 38 million years ago), but it did not arrive in Eurasia until the Miocene. There is some suggestion that Parictis may have emigrated from Asia into North America during t...