Organism · Dinosaurs
Tarbosaurus bataar
Source time context (not species duration) · ≈ 143–66 Ma
Inferred life reconstruction
Tarbosaurus bataar
Overview
Tarbosaurus bataar was a tyrannosaur from Late Cretaceous Mongolia. Juvenile fossils reveal the growth of a giant predator. Their skulls and teeth are interesting because they were not simply scaled-down versions of the adult.[1]
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Key facts
Specimen MPC-D107/7 is estimated to have died at about two or three years of age. Growth traces in the tibia and fibula were compared to investigate its age. This fossil allows the shape of a small skull to be read alongside a record of growth.[1]
Time and place
It was a Mongolian dinosaur of the Late Cretaceous, around 70 million years ago. The juvenile specimen came from the Nemegt Formation at Bugin Tsav in the present-day Gobi. Sediments deposited by meandering rivers preserved organisms of that time.[1]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
The juvenile specimen’s skull is about 29 cm long. It is low and elongated, with more slender, weaker structures and teeth than the adult. Much of the postcranial skeleton remains articulated, although the neck, anterior back vertebrae, and substantial portions of the tail tip are understood through separate comparisons.[1]
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Habitat and reproduction
Researchers proposed that juveniles and adults may have eaten different prey. Slender teeth and a lightly built skull suggest ways of processing food different from those of the adult’s powerful skull. Its ecological role, as well as its body, may have changed as it grew.[1]
Fossil discovery
The juvenile skeleton was discovered during an expedition in the Mongolian Gobi in 2006. A 2011 study analyzed the skull, CT data, and bone growth lines together. Examining a juvenile specimen alongside large adults enriched the story of this species’ life.[1]
References
- Tsuihiji et al. (2011) — Juvenile Tarbosaurus bataar MPC-D107/7 · Journal of Vertebrate Paleontology 31(3), proof hosted by the author’s institution
- Wilson2005 — Reexamination of the skull of Nemegtosaurus
- Currie et al.2018 — Rediscovery of Nemegt sauropod localities
- Osmólska & Roniewicz1970 — Deinocheiridae
Research questions
How does a predator’s face change as it grows? Comparing juvenile and adult Tarbosaurus skulls reveals variation within one species. Fossils of Nemegtosaurus and Deinocheirus also illustrate the diverse dinosaur world of the Nemegt Formation.[1][3][4]
Observation
First examine the juvenile’s low, elongated skull and slender teeth. Imagining them alongside the adult’s taller skull makes changes in proportions during growth easier to see.[1]
Related organisms
Nemegtosaurus mongoliensisDinosaursSource time context (not species duration) · ≈ 143–66 MaA long-necked neighbor in the Nemegt Formation
The Nemegt Formation in Mongolia preserves fossils of the long-necked Nemegtosaurus as well as Tarbosaurus. Together they offer a view of the diverse dinosaur world represented in the same formation.
Deinocheirus mirificusDinosaursSource time context (not species duration) · ≈ 143–66 MaA large-forelimbed neighbor in the Nemegt Formation
The Nemegt Formation in Mongolia preserves fossils of Deinocheirus, with its enormous forelimbs, as well as Tarbosaurus. Together they offer a view of the diverse dinosaur world represented in the same formation.