The gastropod Protosurcia gabbi lived in the Eocene.  Specimen found in the Stone City Formation (aka Whiskey Bridge) of Brazos River, ...

Mooreoceras conicum cephalopod fossils found in the Finnis Shale of Jacksboro, Texas. Creatures swam around in the Pennsylvanian Period....

Coronia genitiva gastropod found in the Brazos River, Texas. Animal lived in the Eocene.  Fossil found in the Stone City Formation (Whisk...