Tarbosaurus bataar (Maleyev), 1955

Russell, Dale A., 1970, Tyrannosaurs from the Late Cretaceous of western Canada, Ottawa: National Museum of Natural Sciences, Publications in Palaeontology, No. 1 : 20

Tarbosaurus bataar (Maleyev)

This species is known from the remains of at least seven individuals collected by the Palaeontological Institute of the Academy of Sciences of the U. S. S.R. ( Maleyev 1955 b, 1955c) and six more collected by the Polish-Mongolian Palaeontological Expedition ( Kielan-Jaworowska 1967), all from the Nemegt basin in strata that may be approximately Edmontonian {see L. S. Russell 1963) in age. The form has not yet been thoroughly described, although it has been the subject of several brief reports {see Introduction) and a cast of the skull of one specimen (NMC 10422) was available for study through an exchange with the Palaeontological Institute. Tarbosaurus seems to be most closely allied to Tyrannosaurus . It differs from this genus in that the nasals are not quite so constricted between the lacrimals, the frontals do have some dorsal expression (but not so much as in Albertosaurus or Daspletosaurus ), the surangular foramen is small, and adult animals are smaller than adult specimens of Tyrannosaurus . (I am indebted to Dr. A. K. Rozhdestvensky for the above information on the morphology of Tarbosaurus .)