The enormous and varied appetite of "Tylosaurus" can been demonstrated in a 1987 find that identified fossils of a mosasaur measuring or longer, the diving bird "Hesperornis", a "Bananogmius" fish, and possibly a shark all within the stomach of a single "T. proriger" skeleton (SDSM 10439) recovered from the Pierre Shale of South Dakota. Other records of stomach contents include a sea turtle in a "T. bernardi"-like species, a long "Dolichorhynchops" in another "T. proriger", partially digested bones and scales of a "Cimolichthys" in a third "T. proriger", partially digested vertebrae of a "Clidastes" in a fourth "T. proriger", remains of three "Platecarpus" individuals in a "T. nepaeolicus", and "Plioplatecarpus" bones in a "T. saskatchewanensis". Puncture marks on fossils of ammonites, the carapace of a "Protostega", and the gladius of an "Enchoteuthis" have been attributed to "Tylosaurus".