WASHINGTON (AP)--A crocodile longer than a school bus and weighing about 10 tons was the top predator in an African river 110 million years ago, routinely dining on large dinosaurs that came within range of its toothy jaws.
"When this thing grew into an adult it was really a monster," Paul C. Sereno, a well-known dinosaur hunter at the University of Chicago, said in an interview. "This thing could have easily pulled down a good-sized dinosaur."
Fossils of the monster croc were uncovered in a desert in Niger last year by Sereno and his team. The species, called Sarcosuchus imperator, or "flesh crocodile emperor," was first discovered by French scientists in 1964, but the Sereno find is the most complete fossil skeleton known.
"This new material gives us a good look at hyper giant crocodiles," said Sereno in a statement. "No one had enough of the skull and skeleton to really nail any of the true croc giants until now."
A report on the discovery is to be published by the journal Science on its Website Science Express.
Sereno said that the elongated skull of the Sarcosuchus (pronounced SARK-oh-SOOK-us) is about six feet in length and dominated by narrow jaws studded with more than 100 teeth. The upper jaw, tipped with large, sharp and powerful incisors, overlaps the lower jaw, an ideal design to lock and hold onto flesh.
"The teeth are incredibly stout," he said. "They are crushing, penetrating teeth," which means the animal probably fed on land animals more than on fish and turtles, the most common food of modern crocodiles and alligators.
Sereno said the animal's eye sockets are rotated upward, enabling it to remain submerged in water while watching the shoreline.
"This suggests it was an ambush predator, hiding under the water and then surging out to grab anything lounging on the shore," he said.
Modern crocodiles living in African rivers often grab large animals, such as wildebeest and zebras, and drag them into the water where they are drowned and then torn apart.
Sarcosuchus probably did the same thing, said Sereno, but because the ancient animal was so large it could easily handle huge dinosaurs, including the massive long-necked, small-headed sauropods that were common in that African region.
"A small sauropod, 20 or 30 feet in length, would have been no problem," said Sereno. He said the giant crock probably remained still in the water until an animal came to drink and then it whipped its jaws out and sunk its teeth into its prey.
"And that would have been it," Sereno. "Once one of these clamped onto the leg or neck of an animal, there wasn't a lot it (the victim) could do."