Teratophoneus

Phylogeny: Dinosauria > Saurischia > Theropoda > Neotheropoda > Tetanurae > Avetheropoda > Coelurosauria > Tyrannosauroidea > Pantyrannosauria > Eutyrannosauria > Tyrannosauridae > Tyrannosaurinae > Teratophoneini

Overview: As the Late Cretaceous wore on, the large predator niches in North America were slowly being taken over by tyrannosaurids. Among these were a handful belonging to a lineage seemingly unique to the American southwest, classified within a tribe called the Teratophoneini. Members of this group were a part of the subfamily Tyrannosaurinae, so they were closely related to dinosaurs like Tyrannosaurus and Tarbosaurus. The tribe takes its name from Teratophoneus, one of its more well known members, found within the rocks of Utah’s Kaiparowits Formation. It was geologically younger than its relative Lythronax, having lived about seventy-six million years ago. Described as a genus in 2011, the name of Teratophoneus is derived from Greek, meaning “monstrous murderer” in reference to its inferred ferocity, size and status as an apex predator within its environment.

Teratophoneus is currently known from around a half dozen specimens, so its general appearance is fairly well understood. It was a medium to large-sized tyrannosaurid, growing to be about seven or eight meters in length, so about the same size as its close relatives like Lythronax. The jaws were deep, suggesting it had a decent bite force. Tyrannosaurids mainly relied upon their jaws to kill, the arms tending to be relatively short and with only two digits on each hand. Major sources of food for Teratophoneus may’ve included a species of the hadrosaur genus Parasaurolophus and a few ceratopsids like Nasutoceratops or Kosmoceratops. These dinosaurs lived along a fairly humid and lush coast, with the center of North America being submerged by the Western Interior Seaway. In the region’s waterways prowled the gigantic crocodilian (or crocodilian relative) Deinosuchus, which was a threat to this animal itself.