Tarbosaurus, meaning “alarming lizard” is a genus of tyrannosaurid theropod dinosaur that thrived in Asia about 70 million years ago, at the end of the Late Cretaceous Period. Fossils have been uncovered in Mongolia, with more incomplete remains found further afield in parts of China.

Many species have been named, although, modern paleontologists recognize only one, T. bataar, as legitimate.

Like most tyrannosaurus, Tarbosaurus was a sizeable bipedal predator, weighing up to six tons and outfitted with sixty large teeth. It had a distinctive locking mechanism in its lower jaw and the smallest forelimbs comparative to body size of all tyrannosaurus, famous for their disproportionately tiny and two-fingered forelimbs.

This dinosaur inhabited a humid floodplain criss-crossed by river channels. In this evironment, it was an apex predator at the top of the food chain, most likely preying upon other large dinosaurs such as the hadrosaur Saurolophus or the sauropod Nemegtosaurus. Tarbosaurus is very well represented in the fossil record, known from dozens of samples, including several whole skulls and skeletons. These remains have enabled scientific studies concentrating on its phylogeny, brain structure, and skull mechanics.

Although it was smaller than Tyrannosaurus, Tarbosaurus was one of the biggest tyrannosaurids. The largest known individuals were between 30 and 40 feet long. The mass of a fully grown individual is considered equivalent to or somewhat smaller than Tyrannosaurus. The largest known Tarbosaurus skull is more than 4 ft long, which is larger than all other tyrannosaurids except for Tyrannosaurus. The skull was tall, much like that of Tyrannosaurus, but lacking in wideness, especially towards its rear. The unexpanded rear of the skull meant that the eyes didn’t face directly forwards, proposing that it lacked the binocular vision of Tyrannosaurus.

Most of the specimens of Tarbosaurus are representations of adult or sub adult individuals, the juveniles being a very rare find. Nevertheless, a 2006 discovery of a juvenile skeleton including a whole, .95 ft long skull provided information of the dinosaur’s life history. This individual was most likely aged 2 to 3 years at the time of death. When compared with adult skulls, the juveniles were weakly constructed and the teeth were thin, demonstrating different food preferences in the juveniles and adults that reduced the competition between different age groups.

Image Caption: Tarbosaurus. Credit: FunkMonk / Wikipedia (CC BY-SA 2.0)