Ancient African Mammals

Long extinct but newly discovered.

The fossils help fill a huge gap in the evolutionary history of African mammals known as the "missing years," shedding light on the origin and distribution of the famed beasts that roam Africa today[...]

"Everything people think they know about African mammals—giraffes, antelopes, lions, cheetahs, rhinos—they all are newcomers," said Tab Rasmussen, an anthropologist at Washington University in St[...] Louis.

This (Oligocene/Miocene boundary) knowledge gap, known as the "missing years," extends from 24 million to 32 million years ago. At that time, the Red Sea had not yet begun to rift open and Africa and Arabia were still joined as a single continent that was isolated from the rest of the world.

To paraphrase MC Rumsfeld, "The more known knowns we know, the more unknown unknowns become known; this we know."

"We are down to two maybe three million years to when we first get Eurasian forms coming in [to Africa]," said Kappelman. "Did some go extinct before the influx, or was it head-on competition that drove them to extinction? That is what we don't know yet."

Maybe the modern African mammals came over on boats. Either way, though, exotic invasives are nothing new.