Pachydermata

Pachydermata (meaning 'thick skin', from the Greekπαχύς, pachys, 'thick', and δέρμα, derma, 'skin') 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 was identified from genetic studies.