The brooding dinosaur

Jeff Poling

In the hills of Mongolia's Gobi Desert, scientists have discovered a unique fossil of a carnivorous dinosaur nesting on its eggs like a brooding bird, revealing for the first time how Earth's most fearsome parents may have tenderly cared for their young.

The 80-million-year-old fossil suggests that the nesting behavior so common among birds today may have originated long before modern feathers and wings, reinforcing the intimate evolutionary link between birds and dinosaurs. It proves they share complex behavior, several dinosaur experts said, as well as important anatomic features. Indeed, the sandstone fossil of a 9-foot-long, beaked carnivorous dinosaur called an oviraptor, preserved with a nest and a brood of unhatched young, is the sole direct evidence of any dinosaur behavior, experts said.

Until now, scientists could only make educated guesses about parental care among dinosaurs, by studying fossil nests and young dinosaurs. The fossil of the oviraptor on its eggs offers the first concrete proof that dinosaurs actively protected and cared for their young, said researchers from the American Museum of Natural History and the Mongolian Academy of Sciences who made their find public yesterday.

"What makes this specimen so spectacular is that, while there is a lot said and a lot written about dinosaur behavior, there is very little real evidence," said Mark A. Norell, associate curator of vertebrate paleontology at the American Museum of Natural history, who led the team that discovered the bones. "This is about the only piece of hard evidence we have."

David B. Weishampel, a dinosaur expert at Johns Hopkins University, called the discovery "astonishing and incontrovertible evidence."

Jack Horner, curator of paleontology at the Museum of the Rockies in Bozeman, Mont., said it was "the strongest evidence of some kind of parental attention."

Jacques Gauthier, curator of reptiles at the California Academy of Science, said the find "opens all kinds of possibilities."

Norell and his colleagues, like many dinosaur experts, are convinced that all modern birds are the direct descendants of a group of meat-eating, biped dinosaurs called theropods, a group that includes the oviraptor, the rapacious Velociraptors made famous in Jurassic Park, and Tyrannosaurus rex. Indeed, to the scientists, under modern methods of grouping animals, birds are dinosaurs. However, many ornithologists do not subscribe to that theory. Several said the new fossil was unconvincing, circumstantial evidence.

Alan Feduccia, at the University of North Carolina, an outspoken critic of the dinosaurian ancestry of birds, said the fossil "makes no sense" and challenged the way its discoverers have linked their find to the development of birds.

"I have no faith in their conclusions whatsoever," he said. "It is a stretch of credulity. There are numerous animals preserved in bizarre poses. Maybe it was laying an egg instead of brooding the eggs. That would make more sense."

As presented by the American Museum of Natural History yesterday, however, the fossilized rock captures a moment more than 80 million years ago when a bipedal, meat-eating dinosaur roughly the size of an ostrich, with a long tail and six-inch claws, protected its clutch of 15 large eggs.

Perhaps overtaken by a sudden sandstorm, the dinosaur was preserved as it lay on the eggs. Its arms are turned back to encircle the nest and its legs are tucked tightly against its body, identical to the nesting posture of birds living today.

For more on the finds of the AMNH's recent expeditions to the Gobi, read Dinosaurs of the Flaming Cliffs.