24 March 2009

Predator X: monster of the deep

by Katie Lee
A fossil of a marine predator the size of a Tyrannosaurus rex and dubbed 'Predator X' has been unearthed at Svalbard in Norway.
Pliosaur

An artist's impression of Predator X. A 45-ton pliosaur crushes its prey with 30-centimetre-long teeth. Credit: Atlantic Productions

BRISBANE: A fossil of a marine predator the size of a Tyrannosaurus rex and dubbed ‘predator X’ has been unearthed at Svalbard in Norway.

The 147-million-year old monster was 15 metres long, had 30-centimetre-long teeth and a bite pressure 10 times greater than any animal alive today, said Jørn Hurum, who led the team that uncovered the fossil.

A new species of pliosaur, predator X was probably an apex predator at the top of the food chain, similar to the modern-day great white shark, said Hurum, a palaeontologist at Natural History Museum at the University of Oslo, Norway.

Skull fragments

Hurum and an international team excavated a partial skull and more than 20,000 fragments of the creature’s skeleton from the permafrost on Svalbard, a remote Arctic archipelago.

The team had excavated another pliosaur at the same location in 2007, and on the last day of the dig noticed more large bones. Returning a year later, they found the partial skull and basioccipital condyle – a spherical bone that connects the head to the vertebrae and allows researchers to estimate the size of the skull.

“Skull material is always exciting, since the head is what the animal uses to navigate through its environment and to feed, so it can tell us much about the ecology of the animal,” said Espen Knutsen, from the Natural History Museum.

Several features of the fossil suggest that predator X was a fearsome hunter. A CT scan of the skull revealed the predator’s brain shape was similar to that of a great white shark, and hydrodynamic testing of the flippers suggesting that the pliosaur used its two front flippers for energy-efficient cruising and its back flippers for bursts of speed during an attack.

Knutsen said that the find helped fill a gap in the fossil record, as few pliosaur fossils have been found from the late Jurassic period (from 160 to 145 million years ago), although they are common during the early Jurassic and the following Cretaceous period.

Cosmopolitan group

“It also adds to the distribution pattern of pliosaurs, giving a picture of animals that were cosmopolitan like certain modern-day whales,” Knutsen said.

The skeleton fragments are now being pieced together by students at the Natural History Museum, and the team hopes to find more material when they excavate at the Svalbard site again later this year, Knutsen said. They are also preparing a documentary and scientific paper describing the find, both to be released later this year.

Steve Salisbury, a palaeontologist at the University of Queensland in Australia, said he was keen to see the paper on predator X for more details.

“It sounds really interesting, but pliosaurs this size are not unheard of,” he said.

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