Word: laurasia
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Dates: during 1990-1999
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...supercontinent known as Pangaea. Because land animals could move and mate at will, dinosaurs from that era look pretty similar all over the world. But by the end of the Jurassic period, about 150 million years ago, continental drift had torn Pangaea into a northern and a southern half, Laurasia and Gondwana. At that point, dinosaurs in each hemisphere should have started evolving along divergent paths. The African dinosaurs should thus most closely resemble those found in South America...
Instead, Carcharodontosaurus closely resembles certain North American carnivores. This implies that the species were exchanging genes well into the early Cretaceous period, which ended perhaps 100 million years ago. Did a bridge of land connect Laurasia and Gondwana after the rest of the landmasses had mostly separated? That's what the new evidence suggests. By 90 million years ago, the separation of continents was evidently complete; Deltadromeus and other African dinosaurs from that period are quite distinct...
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