plastidena

Plastidena is a genus of extinct mammals that lived during the Paleocene and Eocene epochs, around 65 to 56 million years ago. The genus is known from fossil remains found in North America and South America. The name "Plastidena" comes from the Latin word "plastidia," meaning " lap" or "shoe," which refers to the foot anatomy of the genus.

Plastidena is characterized by its distinctive foot morphology, which includes a sturdy, plantigrade foot with a flat, broad shape. The genus is considered to be part of the early radiation of artiodactyls, which are the even-toed ungulates. However, Plastidena is not closely related to any modern artiodactyl families, and its relationships with other extinct mammals remain unclear.

The Plastidena genus includes four known species, P. karlsbadensis, P. lelmuus, P. bigelowi and P. rhenana, all of which have been described from fossil remains found in North and South America. The species are relatively small, with estimated body masses ranging from 10 to 30 kilograms.

The diet and habits of Plastidena are not well understood, but based on the fossil evidence, it is thought to have been a terrestrial or semi-terrestrial animal that likely fed on plants and other herbivorous organisms. The discovery of Plastidena and other early artiodactyls has provided valuable insights into the evolution and radiation of this important group of mammals, and continues to be the subject of ongoing scientific research and study.