Utetitan

Utetitan (meaning "Ute giant") is an extinct genus of titanosaurian sauropod dinosaur from the Late Cretaceous of North America. The genus contains a single species, Utetitan zellaguymondeweyae, known from partial skeletons previously assigned to Alamosaurus. Fossils assigned to this species have been found in the North Horn Formation of Utah, and the Black Peaks and Javelina formations of Texas, United States.

== Discovery and naming == thumb|upright|left|USNM 15560 (Utetitan holotype) quarry in 2013 (top) and 1937 (bottom), North Horn Formation, Utah As part of the Smithsonian Paleontological Expedition in June 1937, George B. Pearce collected a partial skeleton of a large titanosaur sauropod from outcrops of the North Horn Formation on North Horn Mountain in Emery County of Utah, United States. Pearce noted that a sacrum comprising five vertebrae was identified there, but not collected. The specimen, now accessioned at the United States National Museum of Natural History (Smithsonian) as USNM 15560, consists of a partially articulated series of the first 30 articulated with 25 associated , both , and , the right , bones of the right arm (, , , and ), and partial dorsal ribs. In 1946, Charles W. Gilmore described the remains, assigning them to Alamosaurus sanjuanensis, a titanosaur species he had named 24 years prior based on an isolated scapula (USNM 10486) and (USNM 10487) from the Ojo Alamo Formation of New Mexico. Gilmore used the remains to provide an updated diagnosis for the animal, as well as propose an equivalent age for the two formations.