The claw of a giant meat-eating dinosaur (left) dwarfs the claw and vertebra (right) of a cat-sized killer

(Phys.org) -- At least seven different killer dinosaurs once lived in what is now south-eastern Australia, a new study has found.

Research published in PLoS ONE describes the findings of scientists and volunteers from Monash University and Museum Victoria who uncovered a higher than expected biodiversity of meat-eating, theropod (bird-like) dinosaur fossils from between 105 and 120 million years ago.

Honorary Research Fellow Dr. Tom Rich has lead the team collecting dinosaur fossils from the Otway and Stzelecki Ranges of south Victoria for 30 years with colleagues Lesley Kool, Dave Pickering and Professor Pat Vickers-Rich.

The team is associated with both Monash Universitys School of Geosciences and Museum Victoria.

We had not expected to find fossils from such a large range of dinosaur species in this area. The fossils we have collected range from tiny, cat-sized killers to Australias version of T. Rex, a nine-metre-long predator with powerful arms and razor-sharp claws, Dr. Rich said.

In total 1500 isolated bones and teeth of various kinds of dinosaurs have been found in Victoria, Australia so far. Their meaning is only beginning to be unravelled by detailed study and comparisons with other fossils world-wide.

At the time these dinosaurs ruled, southern Australia was part of the Antarctic Circle. Despite the cold, there was a high diversity of small predators, similar to the Velociraptor, featured in Jurassic Park.

One of the reasons for the success of small, theropod dinosaurs may be their warm-blood. As close relatives of birds, they had feathery insulation which helped maintain high body temperatures, Dr. Rich said.

The cool, damp climate may also explain the discovery of the same dinosaur species in both Australia and the northern continents.

The study released in PLoS ONE by University of Cambridge researchers is focused on the discovery of these meat-eating theropod dinosaurs.

Dr. Roger Benson, from the University of Cambridge, said the study reports new discoveries and rationalizes previous investigations.

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