A new study revealed that dinosaurs arose more quickly than previously had thought, and they spread quickly and effectively into the ecosystems in which their ancestors lived.
Scientists have been trying to learn about dinosaurs’ origin. A team of researchers, led by led by Claudia Marsicano, a palaeontologist at the University of Buenos Aires, analyzed fossil-bearing rocks in northwestern Argentina, and found an evidence of a quick transition from pre-dinosaurs to true dinosaurs. According to the research, the transition from pre-dinosaurs to dinosaurs was 5 million to 10 million years shorter than was previously believed.
The study, published in Nature, discredits earlier theories that dinosaurs did not arise until environments changed, giving them a new ecosystem to move into. The latest findings suggest that dinosaurs appeared and spread quickly through the same humid environment that their ancestors inhabited.
“They appear and they start to diversify quite rapidly,” Marsicano says. “They evolved quite successfully.”
The researchers studied a rock formation known as the Chañares, which contains fossils of dinosaur ancestors. The rock lies beneath the Ischigualasto formation, which has preserved remains of some of the earliest known dinosaurs, around 230 million years old.
“If you’re looking to understand the origin of dinosaurs, this is the place to go,” Randall Irmis, a team member and palaeontologist at the Natural History Museum of Utah in Salt Lake City.
Previously, palaeontologists thought the Chañares fossils were between about 247 million to 237 million years old. Now, the new research suggests these fossils are about 5 million to 10 million years younger than previously believed.
According to Irmis, the last dinosaur ancestors was physically different from the first dinosaurs.
“Surely in the near future we will be able to gather an accurate timetable of the key evolutionary steps that resulted in the dominance of dinosaurs on our planet,” says Diego Pol, a palaeontologist at the Museum of Paleontology Egidio Feruglio in Trelew, Argentina.
The study published in the December 7 edition of the Proceedings of the National Academy of Sciences.