Paleontologists know of 527 types of dinosaurs, yet this tally may represent less than one-third of the total diversity, according to Swarthmore statistician Steve Wang and University of Pennsylvania paleontologist Peter Dodson. The team predicts that at the current frantic pace of discovery, 90 percent of discoverable dinosaur genera—more than 1,000—will be identified in the next two centuries.
In 1990, Dodson produced the Dinosauria, a comprehensive compendium of dinosaur knowledge. The book described only 285 genera of dinosaurs; since then, the number of known dinosaurs has increased by 85 percent. "About as many dinosaurs have been described in the past two decades as in all of human history before that," Wang says.
Where are all the missing dinosaurs? According to Dodson, 75 percent of all known dinosaurs have been found in six countries—China, Argentina, Mongolia, Canada, England, and the United States. In the last 16 years, the rate of new dinosaurs identified in Canada has begun to decline, while China's rate has increased by 132 percent. Dodson and Wang's model suggests that dinosaur remains will continue to emerge there and in the United States for years. Dodson practices what he preaches: In the past 20 years he and his students have identified four new dino genera. Last year he named a new specimen Auroraceratops, for the Latin translation of the name of his wife, Dawn. "After 37 years of marriage, I decided it was time to name a dinosaur after her," he says.