Pachydermata (meaning 'thick skin', from the Greek , and ) is an obsolete order of mammals described by Gottlieb Storr, Georges Cuvier, and others, at one time recognized by many systematists. The term ' is commonly used to describe elephants, rhinoceroses, hippopotamuses and tapirs. The grouping was determined to be artificial as a biological classification due to genetic studies.
Description
Pachydermata is an obsolete order of mammals described by Gottlieb Storr, Georges Cuvier, and others, at one time recognized by many systematists. The grouping is polyphyletic, so the order is no longer in use as a biological classification. Outside strict biological classification, the related term ' is commonly used to describe elephants, rhinoceroses, hippopotamuses and tapirs.
Cuvier himself defined Pachydermata as "animals with hoofs, non ruminants", whereas Storr had described it as "mammals with hoofs with more than two toes". The classification Pachydermata included the three families of mammals he called Proboscidiana, Pachydermata Ordinaria, and Solipedes, which are all herbivorous. Cuvier added horses to the order. One naturalist, Delabere Pritchett Blaine, has speculated that:
According to genetic studies, elephants, rhinoceroses, tapirs and hippopotamuses are classified as separate clades altogether. Rhinos, hippos, pigs, peccaries, horses, zebras, donkeys and tapirs are classified in clade Laurasiatheria, while elephants, hyraxes, manatees and dugongs are classified in clade Afrotheria.