†Trinacromerum bentonianum Cragin 1888 (plesiosaur)
Synonyms: Ceraunosaurus brownorum Thurmond 1968, Dolichorhynchops willistoni Riggs 1944, Trinacromerum anonymum Williston 1903, Trinacromerum brownorum Thurmond 1968, Trinacromerum willistoni Riggs 1944
- Trinacromerum bentonianum: USNM 10945. Its type locality is near Downs (USNM), which is in a Turonian marine limestone in the Carlile Shale Formation of Kansas.
- Ceraunosaurus brownorum: SM 3025, a skeleton (nearly complete skeleton). Its type locality is Lake Waco Dam, which is in a Cenomanian marine shale in the Lake Waco Formation of Texas.
- Trinacromerum anonymum: Its type locality is near Paradise Creek (KUVP), which is in a Turonian marine horizon in the Carlile Shale Formation of Kansas.
- Trinacromerum willistoni: KUVP 5070, a partial skeleton (Skull, 50 vertebrae, and most of the girdles). Its type locality is U.S. highway 81 roadcut, south of Concordia (FHSM 1331, T. willistoni type), which is in a Cenomanian marine horizon in the Greenhorn Limestone Formation of Kansas.
Ecology: aquatic carnivore