"We know so much about North American dinosaurs," Sereno says. "Western North America is particularly rich, richer probably than any other single continent," although Asia, particularly China and Mongolia, is providing stiff competition.
Yet, he continues, Asia and North America were connected during the Cretaceous period, so their fossils "are pretty similar. You end up with a very lopsided view of fossil history."
By contrast, he continues, "Africa is a tabula rasa." When he and his research team began working in a section of Niger a few years ago, he says, "there were two named things from this area. Yet from the expeditions we've led, there's an entire menagerie of animals we'll ultimately name and describe."
Nor is he alone. A team led by David Krause at the State University of New York in Stony Brook has been working in Madagascar since 1993 and has uncovered a variety of dinosaurs, birds, turtles, snakes, fish, lizards, mammals, and crocodiles.
"We're trying to get a snapshot of life at that time and in that place," says Catherine Forster, a SUNY-Stony Brook colleague who three years ago reported the discovery of a prehistoric bird whose skeleton blended birdlike features with those of theropod ground-dwellers, thus strengthening the evolutionary link between birds and their dinosaurian ancestors. "We're trying to develop a complete environmental picture of the area."
Earlier this year, an international team led by University of Pennsylvania paleontologist Joshua Smith reported the discovery of an enormous plant-eating titanosaurid at the Bahariya Oasis in Egypt, an area that paleontologists have not explored since 1935.
Drawn to scale, the new creature gives an African elephant all the presence of a toy poodle standing next to Michael Jordan. The area is so rich in fossils that Mr. Smith dubs it "dinosaur heaven."