Cherry Desmostylus hesperus Teeth Cluster

These are the rare teeth of Desmostylus hesperus, an extinct placental mammal from the Middle Miocene Period some 14 - 19 million years ago. Desmostylus leaves no direct descendents, but is likely an ancient, genetic cousin to the sea cow and elephant. This specimen was collected on private land decades ago and only recently became available from an old collection. As the site is no longer collectable, Desmostylus teeth are now very hard to obtain, if at all.

Marsh first described Desmostylus in 1888 from fossils in marine deposits in Alameda County, California. Because of their limited stratigraphic range (Western North America and Japan), the unusual form of teeth that confounds determining what they ate, and their apparent combined terrestrial and marine lifestyle, they are placed in their own Order Desmostyidia within Class Mammalia.

The name Desmostylus derived from Greek means, "linked pillars". These semi-marine mammals had bodies resembling a hippopotamus, with four stout legs and four small tusks. They might have paddled around shallow water crushing shellfish for food with their heavy, columnar teeth or they may have been herbivores, or omnivores. Their closest living relatives are the Proboscidea (elephants) and Sirenia (manatees), such that they belong to the clade Afrotheria. Desmostylians grew nearly two meters in length and are thought to have weighed more than 1500 pounds.