Northward dispersal of dinosaurs from Gondwana to Greenland at the mid-Norian (215–212 Ma, Late Triassic) dip in atmospheric <i>p</i> CO <sub>2</sub>
Dennis V. Kent, Lars B. Clemmensen
Abstract
Significance Sharply contrasting climate zonations under high atmospheric p CO 2 conditions can exert significant obstacles to the dispersal of land vertebrates across a supercontinent. This is argued to be the case in the Triassic for herbivorous sauropodomorph dinosaurs, which were confined to their initial venue in the Southern Hemisphere temperate belt of Pangea for about their first 15 million years. Sauropodomorphs only appear in the fossil record of the Northern Hemisphere temperate belt about 214 million years ago based on a composite magnetostratigraphy of the Fleming Fjord Group in East Greenland. The coincidence in timing within a major dip in atmospheric p CO 2 from published paleosol records suggests the dispersal was related to a concomitant attenuation of climate barriers in a greenhouse world.