(biology) a taxonomic group containing one or more orders

class of cold-blooded air-breathing vertebrates with completely ossified skeleton and a body usually covered with scales or horny plates; once the dominant land animals

extinct mammal-like reptiles found inhabiting all continents from the mid Permian to late Triassic

extinct reptiles of the later Triassic period

edaphosaurus; dimetrodon

class of cold-blooded air-breathing vertebrates with completely ossified skeleton and a body usually covered with scales or horny plates; once the dominant land animals

extinct mammal-like reptiles found inhabiting all continents from the mid Permian to late Triassic

extinct reptiles of the later Triassic period

edaphosaurus; dimetrodon