One hundred million years ago, relatives of Tyrannosaurus. rex roamed Australia.
So say palaeontologists who found a pubic bone in Victoria, Australia, that they believe once belonged to a member of the tyrannosauroid group. It鈥檚 the first piece of evidence showing that T. rex鈥榮 ancestors once lived in the southern hemisphere.
Most palaeontologists had believed that none of the major dinosaur groups, such as tyrannosauroids, were found in both hemispheres, says of Museum Victoria in Melbourne, who discovered the bone in 1989. For example, fossils from the T. rex lineage had only been found in the northern hemisphere 鈥� until now.
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鈥淎s the fossil record improves it鈥檚 becoming more the case that the major dinosaur groups were just about everywhere,鈥� says Rich.
, a colleague of Rich鈥檚 at the University of Cambridge, identified the bone as belonging to a tyrannosaur by its shape and size. Its prominent bulge, called a pubic boot, is distinctive of the tyrannosauroid lineage, says Rich. So are the length of the bone鈥檚 shaft and shape of its tubercle, a fan-like protrusion at the end of the bone.
The bone is similar to one from a fellow tyrannosaur, Raptorex, found in northern China last year. So it is likely that the Australian dinosaur had a similar body shape and size: short arms, powerful jaws and only a third of the size of T. rex.
According to Rich, tyrannosaurs probably roamed throughout the world鈥檚 supercontinent, Pangaea, which existed around 250 million years ago. As the continents began to fragment, however, 鈥渨e no longer see these T. rex-like creatures running around in the southern hemisphere鈥�, says Rich.
, a palaeontologist at the University of Witwatersrand in Johannesburg, South Africa, who was not involved in the work but has seen the fossil, is very excited by the discovery. 鈥淚t鈥檚 interesting to find that tyrannosauroids were definitely here in the south,鈥� he says.
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