Adelobasileus

Adelobasileus cromptoni is a genus of mammaliamorph cynodonts from the Late Triassic (Carnian to Rhaetian), about 225 - 220 million years ago. It is known only from a partial skull recovered from the Tecovas Formation in western Texas and partial specimens from the Chinle Formation in Arizona, Southern United States.

Adelobasileus Temporal range: Late Triassic, 225 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Life restoration
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	Cynodontia
Clade:	Mammaliamorpha
Genus:	†Adelobasileus Lucas & Hunt, 1990
Species:	†A. cromptoni
Binomial name
†Adelobasileus cromptoni Lucas & Hunt, 1990

Distinct cranial features, especially the housing of the cochlea, suggest that Adelobasileus is a transitional form in the character transformation from non-mammaliaform cynodonts to mammaliaforms. For this reason, it is thought to be a close relative of the common ancestor of all modern mammals. Though formerly classified as a mammal by trait-based taxonomy, it is currently placed outside the crown group containing all true mammals.^[1]