Researchers from MIT, Argentina, and South Africa have published a paper looking into the heard activity of dinosaurs. The study found that dinosaurs did move in herds and that they moved in herds much earlier than previously believed. Researchers now believe dinosaurs lived in social herds as early as 193 million years ago.
The researchers detail the discovery of a well-preserved group of early dinosaurs that show signs of complex herd behavior. The discovery was dated to 193 million years ago, putting the date for the development of complex herd activity back an additional 40 million years than previously believed. The researchers have been working since 2013 and have excavated over 100 dinosaur eggs roughly the size of a chicken egg and partial skeletons of juvenile and adult dinosaurs.
All the fossils were discovered in a fossil bed rich in samples in southern Patagonia. The team used x-ray tomography imaging to examine the contents of the eggs without having to break them open. Inside those eggs, preserved embryos were discovered, confirming all of the fossils were members of a plant-eating dinosaur group called Mussaurus patagonicus from the early Jurassic period.
In the same area, the remains of adult dinosaurs were discovered either alone or in pairs throughout the site. The team also found that dinosaur eggs and hatchlings were in one area with skeletons of juveniles grouped nearby. The age segregation of different groups of young dinosaurs is a sign of complex heard-like social structures.
Researchers believe the dinosaurs laid eggs in a common nesting ground with juveniles congregated together while the adults foraged for food for the herd. The team believes the structure they discovered means young didn’t follow their parents in family structures. The evidence shows a larger community structure with adults sharing in raising the community young as a whole. Sediments around the fossils date to 193 million years ago and shows the earliest evidence for social herding among all dinosaurs.