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Tarbosaurus

Maleev, 1955 TAR-buh-SOR-uhs /ˌtɑːrbəˈsɔːrəs/

From Ancient Greek 'tarbos' meaning 'terror' or 'alarm' and 'sauros' meaning 'lizard'.

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Tarbosaurus is a genus of large tyrannosaurid dinosaur that lived in Asia during the Maastrichtian age of the Late Cretaceous epoch. It contains the type and single species Tarbosaurus bataar, which is known from the Nemegt Formation of Mongolia, with more fragmentary remains found further afield in the Subashi Formation of China. Tarbosaurus is represented by dozens of fossil specimens, including several complete skulls and skeletons. These remains have allowed studies focusing on its phylogeny, skull mechanics, and brain structure. Further fossil remains have been reported from other geologic formations of Asia, however, these remains are fragmentary and cannot be confidently assigned to Tarbosaurus or the type species.

Under dispute

The generic placement of the single Mongolian species is long debated. Maleev (1955) named the type material Tyrannosaurus bataar (holotype PIN 551-1) and, in a companion paper, erected Tarbosaurus for the related Tarbosaurus efremovi. Rozhdestvensky (1965) interpreted Maleev's several Mongolian species as growth stages of one animal and, keeping the genus Tarbosaurus, coined the combination Tarbosaurus bataar. Carpenter (1992) judged the differences from Tyrannosaurus to fall within normal individual and ontogenetic variation and sank Tarbosaurus into Tyrannosaurus (Tyrannosaurus bataar), whereas Olshevsky, Ford and Yamamoto (1995) instead split the material among Tarbosaurus, Jenghizkhan and Maleevosaurus. Most work since 1999 recognizes a single species; the majority retains Tarbosaurus bataar, with a minority (e.g. Carr and others) treating it as Tyrannosaurus bataar.

Diagnosis

  1. Large skull, massive, with 2 large premaxillary foramina and third small foramen between premaxilla and maxilla
  2. Pisolitic orbits
  3. Maxilla long, raised, equipped with powerful saber-like teeth, slightly compressed and serrated marginally
  4. Short neck consisting of 8-9 opisthocoelous cervical vertebrae
  5. Forelimbs extremely reduced; humerus very short with strong deltopectoral crest; proportion of humerus to scapula 3:1
  6. Pubic symphysis strongly elongate anteriorly and curved ventrally forming powerful bony foot

Species

Tarbosaurus bataar (Maleev, 1955)

Type species

First named as Tyrannosaurus bataar

From Mongolian 'baatar' meaning 'hero', though the original spelling was a misspelling of the word.

Holotype
PIN 551-1 , Paleontological Institute, Russian Academy of Sciences
Material
Skull and postcranial skeleton.
Horizon
Nemegt Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Nemegt, Ömnögovi, Mongolia

Synonyms

  • Gorgosaurus lancinator junior subjective

    Named by Maleev (1955); synonymized with T. bataar as a growth stage by Rozhdestvensky (1965).

  • Gorgosaurus novojilovi junior subjective

    Named by Maleev (1955); made the basis of Maleevosaurus by Carpenter (1992) and later regarded as a juvenile Tarbosaurus.

  • Shanshanosaurus junior subjective

    S. houyanshanensis has been provisionally accepted as referable to Tarbosaurus bataar.

  • Tarbosaurus efremovi junior subjective

    Named by Maleev (1955) on PIN 551-2 as the type species of Tarbosaurus; treated as a growth stage of T. bataar since Rozhdestvensky (1965).

  • Tyrannosaurus bataar reassigned

    Original combination (Maleev, 1955, on holotype PIN 551-1); recombined as Tarbosaurus bataar by Rozhdestvensky (1965). Still used by authors who regard the taxon as an Asian species of Tyrannosaurus.

Synonyms of the genus

Name Type Reason
Jenghizkhan possible subjective Paul (2025) lists Jenghizkhan among the synonyms of Tarbosaurus but marks it doubtful, and offers no supporting discussion; the name is Paul's own coinage.
Maleevosaurus junior subjective Erected by Carpenter (1992) for Gorgosaurus novojilovi; now generally interpreted as a juvenile Tarbosaurus.

Notable specimens

  • MPC-D 107/7

    Paleontological Center, Mongolian Academy of Sciences Found 2006 ontogeny

    A rare juvenile, probably 2 to 3 years old, with a complete 290 mm skull, documenting the life history and growth of Tarbosaurus; its weakly built skull and thin teeth indicate different food preferences in juveniles, and its sclerotic rings suggest crepuscular or nocturnal hunting.

    Tsuihiji et al. (2011)

References

  1. Paul, G. S. (2025). A presentation of the current data on the exceptionally diverse non-tyrannosaurid eutyrannosaur and Tyrannosaurini genera and species of western North America during the end Cretaceous North American interchange. Mesozoic 2(2): 85-138. doi:10.11646/mesozoic.2.2.1

    Lists Jenghizkhan among the synonyms of Tarbosaurus, marked doubtful.

    paul2025b
  2. Tsuihiji, T.; Watabe, M.; Tsogtbaatar, K.; Tsubamoto, T.; Barsbold, R.; Suzuki, S.; Lee, A. H.; Ridgely, R. C.; Kawahara, Y.; Witmer, L. M. (2011). Cranial osteology of a juvenile specimen of Tarbosaurus bataar (Theropoda, Tyrannosauridae) from the Nemegt Formation (Upper Cretaceous) of Bugin Tsav, Mongolia. Journal of Vertebrate Paleontology 31(3): 497-517. doi:10.1080/02724634.2011.557116 tsuihiji2011a
  3. Maleev, E. A. (1955). [New carnivorous dinosaurs from the Upper Cretaceous of Mongolia]. Doklady Akademii Nauk USSR 104(5): 779-783. maleev1955a
  4. Maleev, E. A. (1955). [Giant carnivorous dinosaurs of Mongolia]. Doklady Akademii Nauk USSR 104(4): 634-637.

    Original description of the species as Tyrannosaurus bataar.

    maleev1955b
  5. Rozhdestvensky, A. K. (1965). [Growth changes in Asian dinosaurs and some problems of their taxonomy]. Paleontologicheskii Zhurnal (3): 95-109.

    Established the combination Tarbosaurus bataar, treating Maleev's Mongolian species as growth stages.

    rozhdestvensky1965a
  6. Carpenter, K. (1992). Tyrannosaurids (Dinosauria) of Asia and North America. Aspects of Nonmarine Cretaceous Geology 250-268. China Ocean Press, Beijing.

    Reassigned the species to Tyrannosaurus and erected Maleevosaurus for Gorgosaurus novojilovi.

    carpenter1992a
  7. Paul, G. S. (2024). The Princeton Field Guide to Predatory Dinosaurs. Princeton University Press.

    Source of the appearance features.

    paul2024b
  8. Hendrickx, C.; Bell, P. R.; Pittman, M.; Milner, A. R. C.; Cuesta, E.; O'Connor, J.; Loewen, M.; Currie, P. J.; Mateus, O.; Kaye, T. G.; Delcourt, R. (2022). Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs. Biological Reviews 97(3): 960-1004. doi:10.1111/brv.12829

    Documents pebbly body skin from the thoracic region and reticulate scales on referred pedal impressions.

    hendrickx2022a
  9. Olshevsky, G.; Ford, T. L.; Yamamoto, S. (1995). The origin and evolution of the tyrannosaurids (Part 1). Kyoryugaku Saizensen 9: 92-119. olshevsky1995a