Tarbosaurus was a giant tyrannosaurid from Central Asia. Its single recognised species, Tarbosaurus bataar, is known mainly from the Nemegt Formation of Mongolia. The formation is usually placed in the Maastrichtian stage of the Late Cretaceous Period, probably about 72–66 million years ago, although its exact depositional span remains uncertain.
Large adults reached roughly 10–12 metres and about 4–6 tonnes. A massive skull, thick serrated teeth, powerful hind limbs and extremely short two-fingered arms identify it as a close relative of Tyrannosaurus rex, but consistent skull and jaw differences support keeping the Asian animal in its own genus.
Quick facts
| Scientific name | Tarbosaurus bataar Maleev, 1955 |
|---|---|
| Group | Theropoda, Tyrannosauroidea, Tyrannosauridae, Tyrannosaurinae |
| Age | Late Cretaceous, probably Maastrichtian, roughly 72–66 million years ago |
| Range | Southern Mongolia, chiefly the Nemegt Formation; some Chinese referrals are disputed |
| Length | Usually about 10–12 m in large adults |
| Mass | Approximately 4–6 tonnes |
| Diet | Carnivorous; both predation and scavenging were available |
| Locomotion | Bipedal |
| Fossil record | Numerous skulls, partial and near-complete skeletons, juveniles and adults |
What the Nemegt fossils can show
Several well-preserved skulls reveal a narrower rear skull and a different load path through the face and lower jaw than in T. rex.
Juveniles had lower snouts, larger eye sockets, thinner teeth and proportionally longer legs before the skull deepened and bite apparatus strengthened.
Deep grooves and removed tissue on large herbivore bones demonstrate feeding. They do not by themselves distinguish a kill from scavenging.
Several individuals in one region or deposit may reflect water, food or burial processes. Coordinated hunting remains unproved.
Discovery and naming
Major specimens were recovered by the Soviet-Mongolian palaeontological expedition in 1946. Evgeny Maleev described them in 1955, naming the largest skeleton Tyrannosaurus bataar and assigning three others to new species of Gorgosaurus. In 1965 Anatoly Rozhdestvensky showed that much of this variation reflected growth and individual differences, combining the material as Tarbosaurus bataar.
Later Mongolian, Polish, Japanese, Russian, Canadian and other expeditions found many additional animals. The sample includes juveniles, adolescents and adults, making Tarbosaurus one of the best represented giant tyrannosaurids.
Classification and species
Tarbosaurus belongs to Tyrannosaurinae, the robust branch that also includes Tyrannosaurus. Some analyses and authors treat it as Tyrannosaurus bataar. Most recent usage retains Tarbosaurus because the skull combines repeatable distinctions in the nasal and lacrimal region, lower-jaw bracing and proportions. This is a close generic boundary, not evidence of distant relationship. See the wider dinosaur family tree.
Only T. bataar is securely recognised. The small Maleevosaurus novojilovi is usually interpreted as a juvenile, while incomplete Chinese material once called Shanshanosaurus cannot be equated with Mongolian Tarbosaurus without qualification.
Fossils, skull and bite
The record includes near-complete skulls, lower jaws, teeth, vertebrae, ribs, girdles, tiny arms, legs and almost complete skeletons. Deformation and transport affect some specimens, but overlapping material reveals the anatomy well.
Adults carried skulls up to about 1.3 metres long. The head was high and powerful, but narrower behind than in T. rex. Roughly 55–60 teeth occupied the jaws, with D-shaped front teeth and thick serrated lateral teeth. Muscle reconstructions indicate a very strong bite, while exact force values depend on assumed muscle size and the selected skull.
Feeding marks on hadrosaurs, sauropods and Deinocheirus show that the teeth penetrated to bone and stripped tissues from large carcasses. A scavenged Deinocheirus carcass proves carrion feeding on that occasion, not an exclusively scavenging lifestyle.
Body, movement and short arms
The hind limbs carried the whole body and the long tail balanced the head and trunk. Young animals had relatively long, slender legs. Adults became heavier and were unlikely to sustain the extreme running speeds sometimes shown in popular media. A precise maximum speed cannot be read directly from bones.
The arms were exceptionally short and had two functional fingers. Their bones retained muscle attachments, so they were not inert, but their reach was very limited. Suggested roles in rising, mating or holding something close to the chest remain untested. The head and jaws were the principal weapons.
Growth and changing ecology
A well-studied small skull only about 29 centimetres long belonged to a two- or three-year-old animal. Its narrow snout, thinner teeth, large eye sockets and weaker muscle attachments contrast with adults. As the animal grew, the skull deepened, teeth thickened and the feeding apparatus tolerated larger loads.
This pattern supports age-based niche partitioning: agile juveniles may have targeted smaller prey while adults handled larger animals. Specific prey lists remain reconstructions unless stomach contents or diagnostic feeding traces are present. The logic parallels the broader evidence described in how dinosaurs grew.
Nemegt habitat and appearance
The Nemegt Formation records large river channels, floodplains, lakes, wetlands and wooded areas, wetter than the desert settings in older Gobi formations. Hadrosaurs such as Saurolophus, sauropods, Deinocheirus, therizinosaurs and armoured dinosaurs shared this ecosystem.
Small patches of tyrannosaurid skin support scales on preserved regions, but the complete covering of Tarbosaurus is unknown. Neither colour nor facial soft tissues survive. A mainly scaly adult is reasonable; a precise pattern or blanket statement about every body region is not. The evidence limits are explored in dinosaur skin and colour.
Evidence, inference and reconstruction
| Evidence level | Examples |
|---|---|
| Directly preserved | Skulls, teeth, skeletons across growth stages, pathologies and tooth marks on large herbivore remains |
| Strong inference | Giant bipedal predator, powerful bite, continually replacing teeth and major skull change during growth |
| Plausible but unresolved | Age-based prey differences, exact adult speed, preferred prey and functions of the arms |
| Unknown | Colour, complete covering, calls, courtship and organised pack hunting |
Frequently asked questions
When and where did Tarbosaurus live?
It lived in Late Cretaceous Mongolia, mainly in the Nemegt Formation, probably about 72–66 million years ago.
How large was Tarbosaurus?
Large adults were about 10–12 metres long and are commonly estimated at roughly 4–6 tonnes.
Was Tarbosaurus a species of Tyrannosaurus?
The two were very close relatives. Some researchers use Tyrannosaurus bataar, but most current work retains the distinct genus Tarbosaurus.
Did Tarbosaurus hunt in packs?
No direct evidence demonstrates organised pack hunting. Associations can form around carcasses, rivers or burial sites for several reasons.