Dinosaurs Evolved Faster Than We Thought

That shaves about 10 million years off the previous evolutionary timeline.

This study has added a fresh take on when dinosaurs have evolved from their reptile predecessors. The results showed the time passed between the introduction of early dinosauromorphs and the origin of dinosaurs is much quicker than previously thought.

By analysing the ratio of uranium to lead in zircon crystals in this volcanic ash, Dr Irmis and an worldwide team of colleagues were able to precisely date when the zircon was formed and thereby establish an upper limit for the age of the fossils preserved within the ash-containing sediment. “They evolved quite successfully”.

Scientists said that there exists not much difference between the early dinosauromorphs and dinosaurs.

Known for harboring the fossils of early dinosaur relatives, the Chañares Formation is approximately 75 meters thick and is made up of sediments from rivers, lakes and streams that existed during the Triassic period.

“The story is that there was a very rapid evolution and a very rapid achievement of dominance in the fauna as they go from [early] dinosauromorphs to dinosaurs”, affirmed Kenneth Lacovara from Rowan University in New Jersey. Scientists said that dinosaurs used to have a ball-and-socket hip that could rotate easily and additional sacral vertebrae, which helped strengthened the hips. But, none of the studies have helped them know about the age of the rocks containing fossils of these early dinosauromorphs. They were able to track a more precise date through analyzing the zircon minerals, and the amount of uranium they trapped.

Over time, uranium decays into lead and the zircon begins to incorporate lead into its structure. So, an overall mix of creatures dominated by early dinosaurs didn’t really look that much different from earlier ones where dinosauromorphs were predominant, he notes. Irmis said that there were some dinosauromorphs that were present even 20 million after dinosaurs emerged. These changes helped dinosaurs prosper until the 6-mile-long (10 kilometers) asteroid wiped them out 66 million years ago, Irmis said.

This is very big news for paleontologists, as it shows them a very progressive evolution of the dinosaurs and their ancestors, as well as disproving the old theory that the dinosaurs managed to take control of the world following a mass extinction. According to a paper published Monday by an worldwide team of researchers investigating the Chañares Formation in northwestern Argentina, dinosauromorphs – the animals that evolved into dinosaurs – bulked up over less than five million years.

“If you wish to constrain a major evolutionary event, like the beginning of a group or the diversification of a group, the methodology has to have a margin of error that is much smaller”, explained study author Claudia Marsicano, a University of Buenos Aires paleontologist.