Dinosaurs A to Z
Tyrannosauridae

Tarbosaurus bataar TAR-bo-SOR-us

"Alarming lizard"

Tarbosaurus silhouette
You 1.8 m (5.9 ft) tall
Tarbosaurus 10 m (33 ft) long
as long as 6 people standing fingertip to fingertip
silhouette · T. Michael Keesey (CC-BY) via PhyloPic
Length
10 m (33 ft) — About 10 m long, ~5 tonnes — the Asian counterpart to T. rex.
Period
Late Cretaceous (70–66 Mya)
Place
Asia · Mongolia · China
Food
Carnivore — Large prey, especially hadrosaurs like Saurolophus that shared its territory.
Clade
Tyrannosauridae Dinosauria Saurischia Theropoda Coelurosauria Tyrannosauroidea Late-Cretaceous tyrants: T. rex, Tarbosaurus, Albertosaurus.

An Asian tyrannosaur with a locking jaw, 60 teeth, and the tiniest arms of any tyrannosaurid.

Tarbosaurus was the Asian cousin of Tyrannosaurus rex, hunting across Mongolia and China at the same time T. rex ruled North America. The two genera are so similar that paleontologists still argue whether they should be separate at all, or just one widespread tyrannosaur split between continents.

More about Tarbosaurus

Discovery

Named by Evgeny Maleev · 1955 · the Nemegt Formation of the Gobi Desert in Ömnögovi Province, Mongolia

A joint Soviet-Mongolian expedition turned up a large theropod skull and some vertebrae in 1946. In 1955 the Soviet paleontologist Evgeny Maleev made this specimen the holotype of a new species, which he first named Tyrannosaurus bataar.

The genus name comes from Ancient Greek: tarbos, meaning "terror", "alarm", "awe", or "reverence", and a second word meaning "lizard". The species name bataar is a misspelling of the Mongolian word baatar, meaning "hero".

Evgeny Maleev. A Soviet paleontologist who in 1955 named and described the holotype along with three other theropod skulls, coining the genus name Tarbosaurus for one of them (T. efremovi).

Is Tarbosaurus really its own genus, or just an Asian Tyrannosaurus?
T. bataar was originally described as a species of Tyrannosaurus, and some experts still see it that way, which would make the name Tarbosaurus redundant. Others keep the genera separate while treating them as very closely related sister taxa. If they are not synonymous, the relationship is still debated.
For the curious → What is the closest known relative of Tarbosaurus?
A 2003 cladistic analysis based on skull features identified Alioramus, also from Mongolia, as the closest relative, since the two share skull traits related to stress distribution. If proven, this would argue against Tarbosaurus being a synonym of Tyrannosaurus and suggest separate tyrannosaurine lineages evolved in Asia and North America, though the discovery of Qianzhousaurus and the Alioramini tribe later complicated this picture.

What we know

  • More than 30 skeletons known, mostly from the Nemegt Formation of Mongolia.
  • Skull was lighter and lower than T. rex but still packed with banana-sized teeth.
  • Tiny two-fingered arms, like T. rex.
  • Lived alongside Therizinosaurus, Gallimimus, and Deinocheirus.

What we guess

  • Whether Tarbosaurus and T. rex are separate genera or two species of the same animal — anatomists are split.
  • How it competed with the giant ostrich-like Deinocheirus, which lived in the same swampy delta.
  • Whether juveniles hunted differently from adults, as T. rex juveniles seem to have.