Millions of years ago, animals from Asia moved into Europe, leading to a mass extinction of native European fauna in an event called the Grande Coupure, or "great break.” But how these animals got to Europe has been a long-standing mystery, writes NBC News’ Denise Chow.
"People have basically known for decades that Asian mammals invaded Europe somehow," K. Christopher Beard, a paleontologist and professor at the University of Kansas, tells NBC. "What was unknown was: How did they do it? What route did they take?"
Now, in a new study in the journal Earth-Science Reviews, an international team of paleontologists from France, the United States and Turkey describe the discovery and history of a continent they’ve dubbed "Balkanatolia" that connected Asia, Africa and Europe. The name was made by combining the names of present-day areas that once made up the continent—the Balkans and Anatolia, a peninsula in Turkey also called Asia Minor.
The scientists conducted a review of old and new paleontological discoveries from the region, per a statement. They were originally hoping to figure out why distinct fossils unearthed in the Balkans and Turkey were inconsistent with other bones found in Europe and Asia, reports Business Insider’s Aria Bendix. "There were a few reports of very weird fossil animals and we literally had no idea what they were doing there," Alexis Licht, a research scientist at the French National Center for Scientific Research and co-author on the paper, tells the outlet.
The research team discovered that around 50 million years ago, Balkanatolia was an island, housing unique species such as marsupials, hippo-like mammals called embrithopods and ancient mammals called pleuraspidotheriids, per Business Insider. Then, around 40 million years ago, the island shifted and allowed animals to move from Asia to it.
The team unearthed a new fossil deposit in Turkey that had mammal bones with clear Asian affinities, per the statement. The bones dated back to around 38 to 35 million years ago. Among the fossils were parts of a jaw bone from a brontothere, an animal similar to the modern-day rhinoceros.
This find led researchers to think that Asian mammals began to colonize Balkanatolia millions of years earlier than the Grande Coupure—that mass extinction of European species.
Around 34 million years ago, more geological changes, including lowering sea levels, connected Balkanatolia to Europe, creating a passage for animals to move between the two landmasses and leading to the Grande Coupure.
Balkanatolia's early history is still unknown. Researchers are hoping to find older fossils that will give them more clues about how distinct animals arrived on the island in the first place, per NBC. "We have animals on Balkanatolia living side by side that never cohabitate anywhere else on Earth," Beard, a co-author on the paper, tells the publication. "How did that happen? How did this strange, unique island get assembled?"