acorntooths

Acorntooths are a group of extinct mammals that lived during the Paleogene period, approximately 66 to 23 million years ago. They are notable for their distinctive teeth, which are characterized by a large, rounded tooth at the back of the upper jaw, resembling an acorn. This tooth, known as the metaconid, is unique to acorntooths and is thought to have been used for crushing seeds and nuts. The group includes several families, such as the Acrobatidae, which is known for its agile, tree-dwelling members, and the Plesiadapiformes, which are considered to be among the earliest primates.

Acorntooths are believed to have evolved from early mammals that fed on seeds and nuts, and they played an important role in the evolution of mammals. They are thought to have given rise to the modern orders of primates and rodents, as well as several other groups of mammals. The fossil record of acorntooths is extensive, with numerous species known from Europe, Asia, and North America. However, their exact relationships and evolutionary history are still a topic of ongoing research and debate among paleontologists.