AboutDavid Prus Expertise I can answer any general questions about dinosaurs and on prehistoric mammals in the Cenozoic. I also know a bit about the media's various depictions of dinosaurs and their inaccuracies. I don't know much about "microfauna"-small animals, or about Paleozoic besides some knowledge about Permian animals. Plants are right out, I'm afraid.
Experience I have been interested in dinosaurs for most of my life, own a large collection of scientific papers and books on the subject, and am a member of the Field Museum in Chicago.
Education/Credentials I am in college, but studied biology and geology both in high school and as a personal effort.
Question Hi 1)the K-T extinction event took place in new mexico.if this event caused the mass extinction, how did it affect areas on the other side of the world like mongolia or india? 2)in the late cretaceous you said that in india the apex predators were the abelisaurids rajasaurus and indosuchus why didn't they expand their range to northern habitats(mongolia).also why tyarannosaurids didn't expand their range to southern habitats(india) and europe. did tyarnnosaurids ineracted with abelisaurids?
Answer Climatic change in one area of the world effects the rest. Look at the El Nino phenomenon-the oceanic currents connect local events with the rest of the world.
Meanwhile, the size of the crater in the Yucatan indicates an impact large enough millions of tons of debris to be ejected into the atmosphere and cover the globe. Major volcanic impacts have caused worldwide dust clouds, and a massive asteroid impact would create an even greater calamity.
The Abeliosaurs and Tyrannosaurs were separated by the ocean. The northern continent of Laurasia (North America and Eurasia) and the Southern Continent of Gondwana (India, Australia, Antarctica, Africa, and South America) became separate spheres divided by oceans, preventing mass migration in the Cretaceous.
Spinosaurs, sauropods, carnosaurs, nodosaurs, and iguanodonts were the last wave of migrations before the continents split and created different environments.
