Middle Eocene Claiborne Invertebrate Fossils

A ten-year study of Middle Eocene invertebrate fossils from the Stone City Bluff locality on the Brazos River in Burleson County, Texas, revealed a large fauna, including 61 species recorded for the first time from this famous site. Four phyla (Annelida, Bryozoa, Coelenterata and Mollusca), including 72 families, 128 genera and 220 species, are identified and illustrated. One specimen from Phylum Brachiopoda is illustrated but not identified.

The stratigraphy of the Stone City Bluff recognizes three Middle Eocene formations. The Sparta (oldest) is overlain by the Stone City and Cook Mountain formations, respectively. These formations are included within the Claiborne Group and are age-dated between 43 to 46 MYA. All fossils are derived from marine units overlying the deltaic Sparta.

This study represents the first attempt to completely collect, categorize and illustrate the entire invertebrate fossil fauna from Stone City Bluff. It will be a useful reference for collectors and scientists studying Middle Eocene localities in Texas and the central Gulf Coast Plain.