- Researchers are studying the remains of 100 dinosaur eggs in Argentina
- Eggs x-rayed and ‘remarkably well-preserved’ dino embryos revealed
- They date back to 193 million years and probably belonged to a large dinosaur herd
- The remains of 80 juveniles and adults were also found around the same area.
Early dinosaurs were sociable and migrated in herds 193 million years ago—40 million years earlier than previously thought, a new study has revealed.
More than 100 eggs in a dinosaur cemetery in the Laguna Colorada Formation in Patagonia, Argentina, complete with embryonic remains still inside, provide the world’s first evidence of herding behavior.
The scans show they belong to the same species—a primitive long-necked herbivore called Mussaurus patagonicus, according to the team of paleontologists at the Massachusetts Institute of Technology.
The shells, with embryos inside, date back to the Mesozoic Era, 193 million years ago, about 40 million years earlier than previous estimates of the beginning of herd behavior.
The fossilized bones of 80 juveniles and adults were also excavated in an area of about half a square mile on the dry shore of a lake.
The eggs and hatchlings were in one area, with nearby juveniles and adults scattered throughout — typical of a complex, social structure, the team said.
New research at a massive fossil site in Patagonia shows that some of the earliest dinosaurs, Mussaurus patagonicus, lived in herds and suggests that this behavior may have been one of the keys to the dinosaurs’ success.
Scientists Use ESRF High-Energy X-Rays to Penetrate Eggs Without Destroying It and Get a Full View Inside It, Discovering the Embryo of Mussaurus Patagonicus
Key Findings: Early Evidence of Dinosaur Herds
Dinosaur skeletons were not randomly scattered throughout the fossil site, but were grouped according to their age.
Fossils of children of dinosaurs were located near the nests.
One-year-old young were found to be closely related to each other, including a group of 11 skeletons in a relaxed posture, suggesting that Mussaurus formed schools.
Adults and sub-adults were often associated in pairs or singly but all within a square mile area.
To determine the age of the juvenile fossils, the scientists cut a thin piece of bone and looked at the bone tissue under a microscope.
All the findings show a well-organized herd structure and are the first record of such complex social behavior in early dinosaurs.
This pre-dates other records of dinosaurs with evolved social behaviors by more than 40 million years.
The scientists compared these results to other fossil egg sites in South Africa and China and suggest that social behavior can be traced back to the time of the dinosaurs.
According to study co-author Dr Jahandar Ramzani, the dinosaurs worked as a community, laying their eggs in a common nesting ground.
The young would congregate in ‘schools’, while the adults roamed around and made forage for the flock.
“This could mean that the youth were not rearing their parents in the small family structure,” Dr Ramzani said.
‘There is a large community structure, where adults share and participate in growing the entire community.’
The eggs are about the size of a chicken egg, and using state-of-the-art X-ray imaging, the team was able to examine the contents without taking them apart.
Within the eggs they found remarkably well-preserved embryos that helped them confirm the identity of Mussaurus patagonicus.
The plant-eater grows up to 20 feet tall and weighs over a ton. It lived in the early Jurassic and is a member of the sauropodomorphs.
They were the forerunners of Brontosaurus, Diplodocus and other massive sauropods – the largest animals that ever roamed the Earth.
According to Dr Ramazani, the fossils point to a communal nesting ground and adults who tended and cared for the young as herds, who said: To borrow a line from the movie ‘Jurassic Park’ – Dinosaurs walk in herds.
‘And they lived in herds 40 million years earlier than the fossil record shows.’
The international team, including experts from Argentina and South Africa, has been excavating the ancient sediments since 2013.
According to Ramezani, living in herds may have provided an evolutionary advantage to Mussaurus and other sauropodomorphs.
More than 100 eggs, complete with embryos still inside, have been excavated in a dinosaur cemetery in the Laguna Colorada Formation in Patagonia, Argentina, providing the world’s first evidence of herding behavior.
The first sauropodomorph fossils were discovered about 50 years ago in the Laguna Colorada Formation.
Scientists named them Mussaurus, which translates as ‘mouse lizard’, because they believed they belonged to a miniature dinosaur.
Large skeletons were found much later – indicating the larger size of Mussaurus adults. But the name stuck.
The bones are closely spaced together in three sedimentary layers, and it is believed that the area was a common breeding ground for the species.
According to Dr Ramzani, the fossils point to a communal nesting ground and adults who cared for the young as a herd, adding: To borrow a line from the movie ‘Jurassic Park’ – dinosaurs walk in herds
The scans show that the eggs are all from the same species – a primitive long-necked herbivorous called Mussaurus patagonicus, explained the team of paleontologists at the Massachusetts Institute of Technology in Cambridge, Massachusetts.
Laguna Colorada Formation
The Laguna Colorada Formation is in Patagonia, Argentina.
It is a geological formation that belongs to the El Tranquillo group and to the Norian, a division of the Triassic-era.
Many dinosaur tracks and remains have been found in this area.
Dinosaurs may have returned regularly to take advantage of favorable weather…