Dinosaurs: Where Did They Live? - The Guardian

When dinosaurs came into existence nearly 230m years ago, all of the world's land masses were joined in one C-shaped "supercontinent", Pangaea. Of course, these earliest dinosaurs may have only lived in certain parts of Pangaea, and the oldest known specimens were all discovered in what is now Argentina.

Starting in the Late Jurassic epoch, around 160m years ago, the continents began to break up, initially into two vast land masses known as Laurasia (to the north) and Gondwana (in the south), before gradually splitting further into the continents we have today.

Consequently, later Cretaceous dinosaur species tend to have been found only on certain continents. For example, fossils of T. rex have only been discovered in North America, with no evidence of it, or any of its close relatives, ever having lived in the southern continents. Whereas a very different bipedal carnivore, Carnotaurus (with bull-like horns) lived in Argentina, and its relatives, the abelisaurids, were restricted to the southern hemisphere.

Most of the UK's dinosaur fossils have been discovered in southern England – coastal sites such as the Isle of Wight and the Jurassic Coast of Dorset; the clay quarries of Surrey (Baryonyx); and the limestone and clay quarries of Oxfordshire and the Cotswolds. Indeed, the first dinosaur bone ever to be described in scientific literature, possibly from Megalosaurus, was recovered from a limestone quarry in Oxfordshire in 1676, while 200 years later the remains of Camptosaurus were found in a brick and tile works near Oxford.

Elsewhere, the most productive dinosaur fossil sites tend to be remote and barren areas where rock is exposed at the surface – such as the Gobi desert in China and Mongolia, and the desert regions of the midwestern United States such as Arizona, Montana and Nevada. Here, fossils from the Late Jurassic and Late Cretaceous epochs have been collected throughout the 20th century, enabling scientists to develop a very good picture of the development of dinosaurs during this time.

The hottest spot of all, however, is currently China, where over the past two decades a huge number of important discoveries have been made in the north-eastern Liaoning province.

And at the end of last year, the world's biggest deposit of dinosaur bones – an estimated 7,600 samples – was reported to have been found in Shandong province on China's eastern coast; mindblowing when you consider that, in normal circumstances, there is perhaps a one-in-a-million chance that a dinosaur bone will form a fossil.