- Scientists in Argentina have discovered over 100 dinosaur eggs and nearly 80 skeletons of the Jurassic-era species Mussaurus patagonicus.
- The eggs, with the embryos still inside, date back 193 million years and reveal the oldest known evidence of “complex social behavior” in dinosaurs.
- More dinosaur news here.
Over 100 Jurassic-era dinosaur eggs and the fossilized bones of 80 dinosaurs called Mussaurus patagonicus – a sauropod – were recently discovered in Argentina at an archaeological site in southern Patagonia. Included in the discovery were an astounding 20 complete skeletons.
The eggs and bones, which date back 193 million years, were all found in an area of about half a square mile, revealing the first evidence of herd behavior in dinosaurs.
“It is a pretty dramatic scene from 193 million years ago that was frozen in time,” said paleontologist Diego Pol of the Egidio Feruglio Paleontological Museum, lead researcher of the study, told Reuters.
Mussaurus, which grew to about 20 feet (6 meters) long and about 1.5 tons, possessed a long neck and tail, with a small head. It was bipedal as an adult but newborns were quadrupedal. Mussaurus lived early in the Jurassic, the second of three periods comprising the age of dinosaurs. It was a relatively large beast for its time – much bigger than contemporaneous meat-eating dinosaurs. Dinosaurs became true giants later in the Jurassic.
“The site is one of a kind,” Pol added. “It preserves a dinosaur nesting ground including delicate and tiny dinosaur skeletons as well as eggs with embryos inside. The specimens we have found showed that herd behavior was present in long-necked dinosaurs since their early history. These were social animals, and we think this may be an important factor to explain their success.”
Interestingly, according to the study published in Scientific Reports, the dinosaur remains were discovered grouped by age at the time of their deaths.
This phenomenon, called “age segregation,” signals a complex social structure, the researchers said, including adults that foraged for meals and cared for the young. The researchers suspect that members of the herd returned to the same spot during successive seasons to form breeding colonies.
“The young were staying with the adults at least until they reached adulthood. It could be that they stayed in the same herd after reaching adulthood, but we don’t have information to corroborate that hypothesis,” said paleontologist and study co-author Vincent Fernandez of the Natural History Museum in London.
Herd behavior also can protect young and vulnerable individuals from attack by predators.
“It’s a strategy for the survival of a species,” Fernandez said.
“To borrow a line from the movie Jurassic Park – dinosaurs do move in herds,” study co-author Dr. Jahandar Ramezani, a geologist at MIT, told Independent. “And they lived in herds 40 million years earlier than the fossil record showed.”
It’s only a matter of time now.