Caseosaurus (/ˌkeɪzioʊˈsɔːrəs/ KAY-zee-oh-SOR-əs) is a genus of saurischian dinosaur that lived approximately 221.5 to 212 million years ago during the latter part of the Triassic Period in what is now Texas, North America.

[6] According to Baron and Williams (2018), Caseosaurus can be distinguished from all dinosaurs (including herrerasaurids, which are placed outside Dinosauria in their analysis) by a distinctive feature: a sharp, well developed ridge connects the midpoint of the supracetabular crest to the preacetabular process.

[6] However, a recent review of early South American dinosaurs has classified it as a nomen dubium without addressing the previous study.

[7] The only specimen of Caseosaurus was discovered in the Tecovas Formation of the Dockum Group in Texas, within sediments deposited during the Norian stage of the Late Triassic period, approximately 221.5 to 212 million years ago.

The paleonvironment of Caseosaurus's included the archosaur Tecovasaurus and other early theropod dinosaurs, some of which left preserved bipedal tracks.