The Reptile Room
The clade Amniota can basically be described as “reptiles”, at least in the more general sense of discussing the evolution of reptiles from amphibians or the evolution of mammals from the mammal-like reptiles. The word reptile can be used either more generally and informally or more specifically than this. The more general and informal sense of the word can include anything perceived as vaguely “reptilian”, including amphibians and often excluding birds. The more formal, precise definition of the word reptile refers specifically to the clade reptilia, which excludes the so-called mammal-like reptiles as well as basal amniotes, but includes birds.