PhD candidate Phil Bell from Australia says he's discovered what appears to be only the second case of dino cannibalism, at the University of Alberta. Bell is holding the lower jaw bone of a Gorgosaurus, which lived 75 million years ago. (Perry Mah, Sun Media)

A University of Alberta researcher has discovered evidence of dinosaur cannibalism -- only the second such case in the world.

It's believed the cannibalism may have taken place 75 million years ago in what's now southern Alberta after a fierce fight between a pair of flesh-eating dinosaurs called Gorgosaurus, seven-metre-long cousins of the larger Tyrannosaurus rex, says researcher Phil Bell, 27.

Two of the menacing beasts either squared off in a fight to the death or one discovered the other's body and gorged on its flesh, said Bell, an Aussie who loves surfing, but was drawn to Alberta because of its wealth of dinosaur fossils.

"We can't be sure whether he killed him and ate him or found him dead and figured it was a free smorgasbord," said Bell, a paleontology PhD candidate.

The revelation came after Bell studied a jawbone discovered in 1996 in southern Alberta of what appears to be a Gorgosaurus with a tooth embedded in it from another dinosaur of the same type.

"The jaw was from an animal about seven metres long and the one that embedded a tooth was about the same size or bigger," said Bell, who made the discovery after checking the bone that had been sitting inside a collections drawer for 15 years at the Royal Tyrrell Museum in Drumheller. Cannibalism refers to animals of the same species eating one another.

Assuming the giant creatures fought to the death, such a battle "wouldn't be a pretty sight," said Bell.

"These creatures would have been two to 2 1/2 tonnes each and if they stood up on their tiptoes, they could look inside a second-floor window.

"These animals were designed for hunting and killing. Their teeth are built like serrated knives for cutting flesh.

"A fight wouldn't be pretty. It would scare the hell out of anyone who was watching it. There'd be a lot of roaring and breaking of branches around it and it would be particularly bloody.

"If you've ever seen two full-grown grizzly bears battling, it's frightening. Add a couple of extra tonnes to that and you've got a mega battle."

Why should people care about such prehistoric matters? "The thing I really love about looking at bite marks is it puts life in the bones. These animals were alive and active and having impressive combats," Bell said.

The only other proven case of dinosaur cannibalism comes from evidence unearthed in Madagascar in 2007, said Bell, who is publishing his findings about the Gorgosaurus in the scientific journal, Lethaia.

KERRY.DIOTTE@SUNMEDIA.CA