Tyrannosaurus bataar Maleev 1955

• Main Author: Paul, G. S.
• Format: Other/Unknown Material
• Language: unknown
• Published: Touchstone Books 1988
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Reptilia; Dinosauria; Tyrannosauridae; Tyrannosaurus; Tyrannosaurus bataar; Osborn; Ursus arctos
• Online Access: https://zenodo.org/record/4424380; https://doi.org/10.5281/zenodo.4424380

SUBGENUS TYRANNOSAURUS (TYRANNOSAURUS) (Osborn, 1906) TYRANNOSAURUS (TYRANNOSAURUS) BATAAR Maleev, 1955 Synonyms— Tarbosaurus bataar, Tarbosaurus efremovi, Gorgosaurus lancinator, Gorgosaurus novojilovi type—PIN 551-1 best specimens—type (skull), PIN 551-3, ZPAL MgD-1/3 (juvenile) time —early to mid-Maastrichtian? of the late Late Cretaceous horizon and locality—Nemegt Formation of Mongolia MAIN ANATOMICAL STUDY—Maleev 1974 [table omitted] [table omitted] Discovered by the Soviet expedition of 1949, this taxa was at first correctly named Tyrannosaurus bataar by E. Maleev. But then he gave a smaller specimen the fine generic title, Tarbosaurus, and T. bataar is often sunk into the latter. But if the very big type skull had been found in North America it would have been assigned to T. rex: they are that alike! So much so that if they did overlap in time—the exact age of the Nemegt is hard to pin down — T. bataar may have even been an interbreeding, geographical subspecies of T. rex, much as the Eurasian brown bear and American grizzly are subspecies of Ursus arctos. T. bataar’s somewhat smaller size might be due to its living in a harsher, more arid habitat. So Maleev was right the first time in making this Tyrannosaurus. The Mongolian predator does have smaller teeth, a shallower snout and mandible, and somewhat different skull roof bones than T. rex. Also, T. bataar’s orbital horns, both before and behind the eye socket, appear to be the smallest among tyrannosaurs. The biggest complete T. bataar and T. rex skulls are the same length, so these individuals were about equal in size. Their skulls also share the same degree of binocular vision. A more serious taxonomic problem is that the many good skulls and skeletons may represent more than one species.18 Maleev and Osmolska believe in two or more, Rhozhdestvensky argues for one.19 Initially, I inclined toward the former view. After all, three species of the big-cat genus Panthera are found in India (lion, tiger, and leopard), and there is always more than one ...