After the Sixth Extinction
Artist’s conception of the ichthyosaur by Raul Martin/National Geographic.
This smiling fellow, known as Thalattoarchon saurophagis, was cruising the oceans about 244 million years ago in what are now the mountains of central Nevada, snapping up smaller fish for dinner. And that, we’re told, is good news. Here’s why:
The world’s largest extinction event ever – the so-called Permian Extinction that killed off up to 96 percent of all animal species – occurred approximately 252 million years ago. But a fossil of Thalattoarchon, which was unearthed four years ago and has been being studied since then, indicates that these top predators were doing their thing just 8 million years later.
Top predators – like tigers, killer whales and great white sharks – are typically the last animals to evolve in an ecosystem since the rest of the ecosystem has to be in place before it can support them.
That means it “only” took 8 million years for the oceans to repopulate with new species after the extinction event.
How long will it take for a new ecosystem to develop in the wake of the disaster that’s now playing itself out?
The scientists who have been studying Thalattoarchon say that this discovery is relevant to what’s happening today since we are now in the early stages of another mass extinction event – the Sixth Great Extinction.
It’s generally believed that the Permian Extinction was precipitated by huge volcanoes. The current extinction, by contrast, is being driven by human activity, as we mine the oceans for fish, destroy the forests, kill off the wildlife on land and pour greenhouse gases into the atmosphere. Depending on how all of this plays out, one of the questions that arise is how long will it take for a new ecosystem to develop in the wake of the disaster that’s now playing itself out.
The answer: perhaps not too long, according to the folks studying Thalattoarchon. Meaning “only” about 8 million years.
The most recent extinction event – the Fifth Great Extinction, which killed off the dinosaurs after an asteroid hit the planet 65 million years ago – enabled the mammals to gain foothold on Earth. Small mouse-sized mammals who could hide and survive underground were better adapted to living through the aftermath of the asteroid strike.
So who might survive the extinction that we humans are causing?
Perhaps animals like raccoons, who are well adapted to living off the trash that we humans leave behind us. And since they’re smart and have good use of their hands, too, they might be well placed to evolve quite successfully.
After all, 8 million years is a lot longer than the 2 million years it’s taken for us humans to evolve from our own ancestors.