A single specimen representing a new species of a Cretaceous homolid crab occurs in the Notopocorystes Assemblage of the Cenomanian Britton Shale (Eagle Ford Group) at Garza-Little Elm Reservoir, Denton County, Texas. Homolopsis pikeae is characterized by an ovate carapace with well-developed grooves, a raised cephalic arch surmounted by spinose areolations, and prominent tubercles on the lateral
... [Show full abstract] margins. The holotype is preserved as an internal carapace steinkern enclosed in an oxidized, phosphatic concretion and associated with abundant invertebrates. Review of the stratigraphic and geographic distribution of Homolopsis shows a pattern of development along the northern margin of the Tethys Seaway in western and northern Europe, and possibly in Australia, during the Early Cretaceous, and immigration into, and evolution in, the opening Atlantic and Western Interior Seaways of North America and northern Europe during the Late Cretaceous. Homolopsis pikeae extends the geographic range of Homolopsis into the Gulf Coastal Plain and its stratigraphic range lower into the Mid-Cretaceous in North America, patterns consistent with previously hypothesized evolutionary development in North America.