Tarbosaurus is a genus of tyrannosaurid theropod dinosaur that flourished in Asia between 70 and 65 million years ago. It was clearly an apex predator of its region, hunting most prey items, such as Saurolophus, one of the largest in its area.Tarbosaurus is very well-represented in the fossil record, known from dozens of specimens, including several complete skulls and skeletons. These remains have allowed scientific studies focusing on its phylogeny, skull mechanics, and brain structure. Some scientists believe that Tarbosaurus was the same as Tyrannosaurus rex, but due to numerous differences in the skull, it is generally accepted the two were separate. Tarbosaurus are indeed best known from Mongolia - at a single site 500 km or so from the capital, Ulan Bataar, 68 specimens have been discovered by Phil Currie of the Canadian Royal Tyrell Palaeontological Museum. This true great Palaeontologist of our age, is a world renowned authority on the study of the Tyrannosauridae. He has proposed, quite recently, outlandish theories on Tyrannosaur behaviour, which although heavily criticised by fellow Palaeontologists, are gaining support. The key theory of contention, is the idea that Tyrannosaurs hunted in packs spanning the age ranges. At his site in Mongolia, Phil Currie hoped that 68 Tarbosaurus bataar, the second largest of the Tyrannosaurs known - only slightly smaller and lighter built that Tyrannosaurus rex - would prove that this was the case. However, further geological investigation of the rocks, proved that in fact, most of the individuals in the small area (literally each skeleton is within a stones throw away) lived over a period lasting roughly over 500,000 years! Obviously, the 'pack of 68', was impossible. However, at least 12 specimens found together of those 68, lived on the same terrace of rock at the same time of the time span duration. This does show that perhaps 12 Tarbosaurus hunted together, or lived together. Even with the much older evidence Phil Currie also found in Canada, of around a dozen or more Albertosaurus - 9-10 metre long Tyrannosaurs that were the slim-line Tyrannosaurus rex of their day 9 million years before Tyrannosaurus rex, and still terrifying killers - his newer findings still do not convince most. His research into modern animals, suggests that as with Lions, pack behaviour would have started young in Tyrannosaurs if it did at all, with adults passing skills to the juveniles by observation of the juveniles. He also studied Komodo Dragons, and how they leave almost nothing on a carcass, and that a dozen or perhaps several dozen Tyrannosaurs would be so brutal a force of nature, that literally no fossil remains of their unfortunate Hadrosaur prey would ever survive the onslaught of the feeding frenzy. Sadly, whilst this is a good idea, in fact the key evidence demanded by the critics of Phil Currie, is indeed a rare (probably unattainable) fossil site where adult and juvenile Tyrannosaurs like Tarbosaurus bataar, are actually found beside a prey item skeleton with bite marks and such. The chances of this, even if it was the case the Tyrannosaurs hunted in unstoppable packs, are mind boggling slim. Afterall, 'normal' fossils, are fortunate enough to form on land, survive tectonism and faulting over geological time, and not be destroyed with exposed to the elements after millions of years - and then to expect such a dramatic life action frozen in time is highly optimistic.
Tarbosaurus didn't feature in the original Walking with Dinosaurs series.
Tarbosaurus featured in Chased By Dinosaurs episode 2, where it was shown to be the top predator of the desert; it hunted such animals as Mononykus, Protoceratops, Saurolophus and Therizinosaurus, yet the latter could put up a sufficiently spirited defense to defeat even this alpha predator, as featured by Nigel Marven in that episode, when a Tarbosaurus is whacked in the face by a Therizinosaurus' giant claws. It is a 12 metre long apex predator, even though it didn't always have its way when faced with Therizinosaurus on perhaps more numerous occasions than not.