Asian invasion.(Asian dinosaurs replaced North American dinosaurs)

New American dinosaur fossils tell of a takeover by visitors from the Far East.

A late-October snowstorm has put paleontologist Jim Kirkland behind schedule. To make up time, our little band of dinophiles zooms down highways and bounces along backcountry roads without concern for state troopers or the suspensions of our rented vans. Three days is little time for Kirkland to show us the lost world of a hundred million years ago that he explores for the Dinamation International Society.

Kirkland's quest is to bridge an evolutionary chasm that yawns between two of the world's best known groups of dinosaurs. About 150 million years ago, at the end of the Jurassic Period, giant long-necked sauropods -- the elephantine archetypes of plant-eating dinosaurs -- plated stegosaurs, and predatory allosaurs dominated western North America. But a mere seventy million years later, they were gone. In their place roamed more compact plant eaters such as duck-billed hadrosaurs and homed …