For Dinosaurs,

A New Wrinkle in Time

* How did dinosaurs come to have those amazing crests and horns on their heads?

The answer appears to be "wrinkled faces." Paleontologist Paul Sereno has found two dinosaurs in the African country of Niger with wrinkles in their skulls.

Scientists think the wrinkles show the location of blood vessels and nerves to help feed the dino hood ornaments. One of the dinosaurs, called Rugops, was a 30-foot-long meat-eater that lived 95 million years ago.

Sereno's discoveries also might help scientists understand how and when Africa, South America, India and Antarctica broke apart millions of years ago.

Three hundred million years ago, there was only one supercontinent, Pangea. But about 200 million years ago, Earth shifts and quakes split Pangea into Laurasia in the northern hemisphere and Gondwana in the south. Plants and animals evolved very differently depending on whether they were in the north or the south.

The southern hemisphere was one big landmass that included what we now call South America, Australia, India, Madagascar, Africa and Antarctica. Wrinkle-faces have been found in other parts of southern hemisphere but never in Africa. Rugops was the first "wrinkle-faced" dino to be found in Africa.

Some paleontologists believe that Africa was the first continent to split off from Gondwana, about 120 million years ago. But Sereno's discovery of a wrinkle-face in Africa may mean that Gondwana split apart all at once because of a huge disruption in the Earth.

Paul Sereno discusses his dinosaur discovery.