Zygorhiza kochii (Archaeocete whale)

A very rare tooth from Zygorhiza kochii, an Archaeocete whale. The Archaeocete is an ancient whale that evolved and became extinct at the end of the Eocene. Archaeocetes lived from about 50 million years ago to about 37 million years ago. The earliest archaeocetes were terrestrial to semi-aquatic animals which probably fed on marine prey. Later archaeocetes were feeding and spending most of their time in the sea, while returning to land to breed and/or give birth. The latest archaeocetes were the first fully aquatic cetaceans. Zygorhiza kochii represents the latter fully aquatic species.  

Please note that all of these Zygorhiza kochii teeth were found in the Santee Limestone Formation from quarries around Harleyville, S.C., and are the finest quality. These teeth are from the Eocene (38 million years ago).