Giant salamander species found in icy ecosystem

Giusia ZhenyaA newly discovered freshwater apex predator with a body length reaching 4.5 meters lurked in swamps and lakes about 280 million years ago. Its broad, flattened head had powerful jaws filled with large pointed teeth, ready to grab any prey unfortunate enough to swim past it.

The problem is that, according to our knowledge, it shouldn’t have been so large, it should have gone extinct millions of years before it was thought to have existed, and it shouldn’t have been found in northern Namibia.”Gaeasia “This is the first time we’ve gotten a good glimpse of a completely different ecosystem that we didn’t expect to find,” says Jason Pardo, a postdoctoral fellow at the Field Museum of Natural History in Chicago and a co-author of the study. Giusia Zhenya This discovery was recently published in Nature.

Same ancestry

“Tetrapods were the animals that first came out of the water about 380 million years ago, maybe even earlier,” explains Pardo. These ancient creatures, also known as stem tetrapods, were the common ancestors of modern reptiles, amphibians, mammals and birds. “Those animals survived until the end of the Carboniferous, about 370-300 million years ago. A few survived and they lived a long time, but they went extinct about 370 million years ago,” he says.

That is why it is sought Giusia Zhenya It was pretty amazing to be found in the 280 million year old rocks of Namibia. Not only was it not extinct when the rocks it was found in were laid down, but it dominated its ecosystem as an apex predator. By today’s standards, it was like stumbling upon a deserted island where animals that had been dead for 70 million years lived, such as a living, breathing T-Rex.

“Skull gaiasia The one we found is about 67 centimeters long. We also found the front part of its upper body. We know it was at least 2.5 meters long, maybe 3.5, 4.5 meters — big head and long, salamander-like body,” Pardo says. He told Ars. gaiasia She was a suction feeder: She opened her jaws underwater, creating a vacuum that sucked her prey right in. But the large, interlocking fangs suggest that a powerful bite was also one of her weapons, probably used to hunt large animals. “We suspect gaiasia also fed on bony fish, freshwater sharks, and perhaps other small creatures gaiasia“, says Pardo, suggesting that it was a slow, ambush-based predator.

But considering where it was found, the fact that it had ample prey to ambush is perhaps even more shocking than the animal itself.

Location, location, location

“The continents were arranged differently about 270-280 million years ago,” says Pardo. At that time, a megacontinent called Pangaea had already broken up into two supercontinents. The northern supercontinent, called Laurasia, included parts of modern North America, Russia and China. The southern supercontinent, home to gaiasiawas called Gondwana, which included today’s India, Africa, South America, Australia and Antarctica. And Gondwana was very cold at that time.

“Some researchers speculate that the entire continent was covered in glacial ice, just as we saw in North America and Europe during the ice age 10,000 years ago,” says Pardo. “Others claim it was more sporadic – there were some patches where ice was absent,” he adds. Still, 280 million years ago, northern Namibia was at about 60 degrees south latitude – roughly where the northernmost limits of Antarctica are today.

“Historically, we thought of tetrapods as [of that time] They were living just like modern crocodiles. They were cold-blooded, and the only way to get big and stay active if you’re cold-blooded is to live in a very hot environment. We used to believe that such animals couldn’t live in a cold environment. Gaeasia Pardo claims that this is simply not true. And it overturns much of what we know about life on Earth. gaiasiaIt is time.