Adelobasileus cromptoni is a species of an extinct genus of mammal from the Late Triassic (Carnian), about 225 million years ago. It is known only from a partial skull recovered from the Tecovas formation in western Texas, southern USA.Roughly contemporary with the mammaliaform Tikitherium, Adelobasileus predates the non-mammalian cynodonts Tritylodontidae and Tritheledontidae by 10 million years.