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Research concludes some dinosaurs were cannibals
by Lorna Benson, Minnesota Public Radio
April 2, 2003

The fossilized bone and teeth of Majungatholus atopus. Marks on the bone appear to match the size and shape of the teeth at the top of the photo. (Contributed photo)

A husband and wife team of dinosaur researchers from Minnesota have discovered the first solid evidence of cannibalism in dinosaurs. Ray Rogers and Kristi Curry Rogers published their evidence on the Majungatholus dinosaurs in the latest issue of the science journal Nature. The researcher found teeth marks on fossilized bones of Majungatholus dinosaurs that could only have been inflicted by one of their own species. The dinosaurs lived in Madagascar some 65 million years ago.

St. Paul, Minn. — New fossil evidence suggests a distant cousin of the Tyrannosaurus rex that roamed the plains of Madagascar millions of years ago regularly dined on its own kind to survive during hard times.

The discovery is the strongest evidence yet that some carnivorous dinosaurs were cannibals. Dinosaur experts say it sheds light on the hardships predators faced in the late Cretaceous period when dinosaurs vanished, possibly as a result of asteroid impacts, widespread climate change and disease.

The research was conducted by Ray Rogers, a geologist at Macalester College, and his wife, Kristi Curry Rogers, the paleontology curator at the Science Museum of Minnesota.

Kristi Curry Rogers says they conducted their work by examining fossilized bones of Majungatholus atopus, a toothy beast the size of a small school bus that was the top hunter 70 million years ago on Madagascar, the island off east Africa.

Majungatholus is a distant relative of T. rex, the fierce hunter that ruled what is now North America. Scientists have speculated that T. rex also was a scavenger and may have eaten other T. rexes killed in fights, but the evidence is not conclusive.

During the late Cretaceous, Madagascar was semiarid and subject to severe climate swings that led to dramatic fluctuations in essential resources. Fossil evidence showed dinosaurs and other creatures were victims of massive die-offs.

When food and water were scarce, scientists believe Majungatholus fed on the remains of other dinosaurs like titanosaurs -- gigantic, long-necked plant-eaters -- and even scavenged the carcasses of its own dead.

Kristi Curry Rogers says sets of parallel tooth marks on the spine and ribs of the specimens matched the size and spacing of Majungatholus' blade-like teeth, suggesting a hungry member of the species stripped the flesh off the bones.

The specimens do not show whether the dinosaur actually hunted down the other Majungatholus as prey or scavenged their carcasses.

"The amazing thing about this discovery is that it's so rare to find that evidence in the fossil record," says Rogers. "This is a rare window into that biological interaction between two different Majungatholus individuals. It's an incredibly rare thing to have preserved 65 million years ... in the past."

Cannibalism is not uncommon in the animal kingdom today, with more than a dozen species practicing it for a variety of ecologic and evolutionary reasons, scientists say. But in ancient Madagascar, the reasons behind Majungatholus' cannibalism appear to be much more basic. Researchers examining 21 bones from two nearly full-grown specimens taken from separate quarries on the island found evidence of intensive feeding in the backbone area.

Researchers ruled out the only other known meat-eating dinosaur in the area -- Masiakasaurus knopfleri -- because its teeth were too small. They also discounted carnivores like crocodiles that have blunt, irregular teeth.

Kristi Rogers says their research may spur a renewed interest in the study of dinosaurs.

"It does provide a window into the biology of this organism that we didn't have before. I think people are going to get really excited about that part of the discovery," says Rogers. "Having the ability to interpret biological phenomena that were happening so very long ago in the past I think is going to open a lot of doors for future research."

Rogers says there are a few other dinosaurs that are thought to have been cannibalistic, but the evidence has been very scanty.

"I think it's going to cause a resurgence of interest in cannibalism among dinosaurs, and I think people are going to spend a lot more time looking carefully at their fossil collections to see what they can find, and see how many more dinosaurs were cannibals. Maybe even herbivorous dinosaurs were cannibals," says Rogers.

(The Associated Press contributed to this report)

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