Pachydermata
Pach`y`der´ma`ta
(păk`ĭ`dẽr´må`tå)| n. pl. | 1. | (Zool.) A group of hoofed mammals distinguished for the thickness of their skins, including the elephant, hippopotamus, rhinoceros, tapir, horse, and hog; the pachyderms. It is now considered an artificial group. |