According to a new study, the earliest known ancestors of dinosaurs, strange four-legged dog-like creatures, branched out from what is now Africa and Antarctica shortly after Earth's largest mass extinction 252 million years ago.
This mass extinction is what scientists believe opened the era of dinosaurs, but before that, a breed of bizarre pig-size creatures known as Dicynodon took over. They were part of a large, dominant group of plant eaters found across the southern hemisphere that benefited from the clean slate that the mass extinction provided.
The study, which was based on recently unearthed fossils from about 10 million years after the mass extinction, suggests that these creatures flourished in Tanzania and Zambia, millions of years before dinosaur relatives were seen in the fossil records elsewhere on Earth.
These discoveries were made from several National Geographic Society and National Science Foundation funded fossil-hunting expeditions conducted in Antarctica, Zambia and Tanzania.
"The fossil record from the Karoo of South Africa remains a good representation of four-legged land animals across southern Pangea before the extinction event. But after the event animals weren't as uniformly and widely distributed as before. We had to go looking in some fairly unorthodox places," said Christian Sidor, a University of Washington professor of biology and lead author of the study paper.
Findings from 10 million years after the mass extinction provide evidence of archosaurs which lead to Nyasasaurus parringtoni, a dog-sized creature with a five-foot tail, according to scientists.
Correction: A previous version of this article incorrectly referred to Tanzania and Zambia as cities and not countries. The Dicynodon fossils are dated from 10 million years after the mass extinction 252 million years ago and not after the extinction of the dinosaurs about 65 million years ago (at the end of the Cretaceous Period).
