This analysis will test the roles of paleoenvironmental distribution and adaptation in the evolutionary origins of tetrapod lineages and the causes of local patterns of faunal turnover in the Texas Early Cretaceous. The well preserved vertebrate fauna being produced from a sequence spanning as much as 15 my includes diverse fishes, amphibians, lacertilians, dinosaurs, and mammals, many of which are new. Faunas are found in the intercalated marine and terrestrial sediments of the Comanche Series, in habitats ranging from open marine shelf to inland semi-arid floodplain. Abundances of vertebrate taxa through the section will be analyzed quantitatively to determine the relationships of taxa to specific environments and their patterns of change through the section. Paleoenvironments will be assessed based on the sedimentary context of vertebrate localities. Building upon samples already in hand the stratigraphic and paleoenvironmental diversity of the vertebrate record will be further developed through a program of screen washing and through quarrying where feasible. Search efforts will focus on poorly sampled stratigraphic intervals in central Texas and on more inland environments preserved to the west and south.
