Reptiles are a group of vertebrate animals. The name "reptile" comes from Latin and means "one who creeps". All living reptile species are cold blooded, have scaly skin, and lay cleidoic eggs. They also have some less obvious features. They excete uric acid (instead of urea), and have a cloaca. A cloaca is a common vent (opening) for the intestines, urinary tract and reproductive ducts. Reptiles also share an arrangement of the heart and major blood vessels which is different from that of mammals.