With razor teeth, foot-long claws and an appetite for fish, this dinosaur roamed Africa 100 million years ago

In this story:

• Bigger and older than T. rex
• Discovery sheds new light on migration
• Related stories and sites

WASHINGTON (CNN) -- A newly discovered species of dinosaur, with huge curved claws and a skull like a crocodile, has been dug up from an African desert, scientists said Thursday.

The new species ran on two legs, was about 36 feet long and had a sail-like fin on its back.

Researchers who found the fossil believe it is a previously unknown species big enough and mean enough to have dominated its world 100 million years ago.

The new species, to be called Suchomimus tenerensis, "was an impressive-sized beast," said Paul Sereno, a University of Chicago paleontologist who led the study.

"If you were standing next to it, your eye level would be at its knee," Sereno said at a news conference at National Geographic headquarters Thursday. "This animal was easily the size of Tyrannosaurus rex. And it was not fully grown."

It would have been a fearsome animal that probably hunted fish as well as land animals, Sereno said in a study being published Friday in the journal Science.

"With its forearms and its jaws, it would have been able to take down just about anything," Sereno said. "It was the dominant predator of its time."

Its long, narrow head strongly resembled that of a crocodile -- a much more ancient species that, unlike the dinosaur, has endured. The name Suchomimus comes from the Greek word for crocodile.

Bigger and older than T. Rex

The animal was shaped generally like the T. rex, with two large hind legs, a powerful tail, forearms and a toothy head, Sereno said.

Suchomimus was a member of a group of animals called spinosaurids that lived in the lands that became Africa, Europe and South America between 90 million and 120 million years ago. At that time, T. rex was just emerging in North America.

The fossil was found in Niger, a central African country on the southwestern edge of the Sahara. In the dinosaur era, the area "was a lush climate that could support many different species of dinosaurs," Sereno said.

Suchomimus had about 100 lightly curved and hooked teeth well-suited to snatching and holding onto prey in much the way crocodiles ambush their food today.

The end of the jaw is tipped with an extra chin-like projection, called a rosette, that contains the largest teeth.

The animal's thumbs were about 16 inches long and tipped with 12-inch claws curved like sickles. The two fingers on each hand had shorter, curved claws.

"The hand is amazing," Sereno said. "It was probably ideal for fishing, for grabbing ... into those large fish."

Discovery sheds new light on migration

Finding this particular species of spinosaurid in Africa indicates they moved around even more than had been thought, the researchers said.

They "represent one of the most successful radiations of terrestrial predators in earth history," Thomas Holtz of the University of Maryland wrote in a commentary.

It's not known how the Suchomimus died, but it apparently was swept into a river, rolled over and over and then was buried by soil. When found in extreme desert, wind had eroded the sands that had covered it for 100 million years.

Other fossils found nearby suggest the area was lush, with water and fish that attracted many predators.

At least four species of fish up to 6 feet long lived in the waters where Suchomimus hunted, Sereno said. There also were giant crocodiles.

"The most common thing we stumbled on is a very long-snouted and very large crocodile," said Sereno. "We collected a 6-foot skull. The crocodile would have been about 50 feet long."

It is likely, he said, that the giant crocodiles and Suchomimus competed for the same large fish, "and I imagine the two squared off."

Soaring above were flying dinosaurs with 12-foot wing spans, poised to attack from the air with wicked teeth and claws, he said. Fossils of those animals also were found.

"We think that area was pretty well maxed out so far as the number of large animals you could put into that environment," said Sereno.

And ruling it all, he said, was Suchomimus.

The Associated Press and Reuters contributed to this report.