Carrolla craddocki: A New Genus and Species of Microsaur from the Lower Permian of Texas

The specimen, comprising a skull and jaws, is assigned to the suborder Microbrachomorpha and tentatively to the family Brachystelechidae on the basis of the structure of the temporal and occipital regions. It is unique among known microsaurs in the possession of marginal teeth with long slender hollow bases and bifurcated crowns and the apparent absence of palatal dentition. Carrolla craddocki, new genus and species, from Lower Permian (Wolfcampian) Belle Plains Formation in Archer County, Texas, is described and figured. If correctly assigned to the Brachystelechidae, Carrolla is the first record of the family in North America, but it was probably not equivalent ecologically to the roughly contemporaneous Brachystelechus of Europe. Carrolla is believed to have been a burrower in hard soils. Its diet may have comprised soft-bodied subterranean invertebrates, but the functional significance which developed cryptic behavior under competitive pressures from surface dwelling reptiles in an increasingly harsh Early Permian environment in North America.