LEEDS, England, April 25 (UPI) -- Like the exodus of early humans out of Africa, dinosaurs made a break from Europe during the Early Cretaceous Period.
Researchers came to the realization after mapping the movement of dinosaur families through the Mesozoic Era, which lasted about 180 million years and included the Triassic, Jurassic, and Cretaceous periods. It's the first time scientists have used "network theory" to visualize dinosaur migrations.
Network theory is an analytical strategy that calls for the use of a wide-angle perspective to visualize the relationships among groups, objects or ideas within a larger system.
A team of paleontologists and Earth scientists from the University of Bath and the University of Leeds used the entirety of the dinosaur fossil record, cross-mapping dinosaur families across time and space.
Their work showed that during the Early Cretaceous, between 125 million and 100 million years ago, dinosaur families were migrating out of Europe but no new families were coming in.
"This is a curious result that has no concrete explanation," lead study author Alex Dunhill, a professor at Leeds' School of Earth and Environment, said in a news release. "It might be a real migratory pattern or it may be an artefact of the incomplete and sporadic nature of the dinosaur fossil record."
Dunhill and his colleagues published their findings in the Journal of Biogeography.
Their analysis also confirmed what researchers had previously hypothesized -- that dinosaurs continued to disperse to the various continents as the "supercontinent" Pangaea split apart.
"We presume that temporary land bridges formed due to changes in sea levels, temporarily reconnecting the continents," Dunhill said.