Roughly 250 million years ago, Earth’s land masses lay together in one supercontinent known as Pangea. Surrounded by a single ocean, known as Panthalassa, it saw the rise of the dinosaurs.
Pangea was roughly shaped like Pac-Man, with land reaching to both north and south poles and a chunk biting into the middle that contained the Tethys Sea, explains Paul Olsen, a paleontologist at Columbia University. Over the millions of years of its existence, this supercontinent saw the flourishing of biodiversity, bookended by two mass extinctions, he adds.
“During the time of Pangea, you really see this replacement of a kind of archaic land and marine fauna by one that looks much more modern,” says Olsen. “By the end of Pangea, you basically have all the major groups of organisms around.”
