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Scientists Unearth Fossil Of Dinosaur Being Attacked By Mammal

The fossil sheds new light on the behavior of early mammals in relation to their dinosaur contemporaries.

An extraordinary fossil of a dinosaur being attacked and eaten by a mammal has been unearthed by paleontologists.

It features the entangled skeletons of a beaked and horned herbivore and the meat-eating Repenomamus—which was smaller.

The amazing scene was frozen in time when a mudslide entombed them both.

Co-author Dr. Jordan Mallon, of the Canadian Museum of Nature, Ottawa, Ontario, said, “The two animals are locked in mortal combat—intimately intertwined.

“It’s among the first evidence to show actual predatory behavior by a mammal on a dinosaur.”

Illustration depicting the battle between the dinosaur and mammal. (MICHAEL SKREPNICK/SWNS)

Close examination shows the dinosaur is lying prone with its hindlimbs folded on either side of its body. Psittacosaurus was about the size of a large dog.

Badger-like Repenomamus, the largest mammal of the Cretaceous, coils to the right and sits atop—gripping the jaw of its prey. It is also biting into some of the ribs. The back foot is holding onto Psittacosaurus’ hind leg.

Dr. Mallon said, “The weight of the evidence suggests that an active attack was underway.”

The international team ruled out scavenging as the bones of the dinosaur have no tooth marks. It’s also unlikely the two would have become so entangled.

Fossil of dinosaur. (GANG HAN/SWNS)

The elevated position of the Repenomamus also suggests it was the aggressor.

Lone wolves are known to hunt larger animals, including caribou and domestic sheep, in the modern world.

On the African savanna, wild dogs, jackals and hyenas will attack prey that is still alive, with the target collapsing, often in a state of shock.

Dr. Mallom said, “This might be the case of what is depicted in the fossil, with the Repenomamus actually eating the Psittacosaurus while it was still alive—before both were killed in the roily aftermath.”

A sketch of how they became entombed after a mudslide. (MICHAEL SKREPNICK/SWNS)

The discovery was made at a prehistoric animal graveyard in Liaoning, dubbed “China’s Dinosaur Pompeii.”

There are also small mammals, lizards, and amphibians buried suddenly en masse by mudslides and debris following volcanic eruptions.

It contradicts the idea dinosaurs had few threats from mammal contemporaries. Repenomamus was known to have preyed on Psittacosaurus because of fossilized baby bones of the herbivore found in the mammal’s stomach.

Both skeletons are nearly complete.

Detail of larger fossil, showing Repenomamus (mammal) biting the ribs of Psittacosaurus (dinosaur). (GANG HAN/SWNS)

 “What’s new to science through this amazing fossil is the predatory behavior it shows,” said Dr. Mallon.

Deposits from the Lujiatun beds will continue to yield new evidence of interactions among species—otherwise unknown from the rest of the fossil record, added the researchers.

The study is published in the journal Scientific Reports.

Produced in association with SWNS Talker

Edited by and

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