Postdoctoral Fellow Publishes In Nature

The fossil is named for the Gai-as Formation in Namibia where it was found, and the late Jenny Clack, a noted paleontologist. In life Gaiasia jennyae would have looked something like a cross between a salamander and a moray eel—at least eight feet long, perhaps up to fifteen—with a long, flexible body, a deep tail fin like that of a gigantic newt, and tiny limbs (or maybe none). With a two-foot-long, flat, squared-off head and huge fangs, it was well equipped to suck in prey. “It’s a big predator, but potentially also a relatively slow ambush predator,” notes Jason, probably hung out near the bottom of swamps and lakes. Claudia Marsicano, the University of Buenos Aires paleontologist who discovered the fossil with colleagues, was initially struck by the structure of the front of the skull. “It was the only clearly visible part at that time,” she recalled in an interview. “And it showed very unusually interlocking large fangs, creating a unique bite for early tetrapods.” The team unearthed several specimens, including one with a well-preserved, articulated skull and spine. Based on the fossils, the team determined that Gaiasia belonged to a family of bigheaded, swamp-dwelling vertebrates called colosteids, which had split off from other land animals long before the ancestors of more modern lineages like amphibians, reptiles and mammals evolved. “It’s really, really surprising that Gaiasia is so archaic,” Jason says. “It was related to organisms that went extinct probably 40 million years prior.” Claudia adds, “It was displaced in time, displaced regionally, and also far too big.” Today Namibia lies just north of South Africa, but 280 million years ago it was further south, near the 60th parallel, almost even with the northernmost point of today’s Antarctica. At that time, the Earth was nearing the end of an ice age; the swampy land near the equator was drying up and becoming more forested, but closer to the poles, the swamps remained, potentially alongside patches of ice and glaciers. There were other archaic animals still hanging on at the time, Jason observes, “but they were rare, they were small, and they were doing their own thing. Gaiasia is big, and it is abundant, and it seems to be the primary predator in its ecosystem.” The broader insights the discovery provides on the Permian are significant. “There were a lot of groups of animals that appeared at this time that we don’t really know where they came from,” says Jason. “The fact that we found Gaiasia in the far south tells us that there was a flourishing ecosystem that could support these very large predators.” News coverage appears in The Independent, BBC/Discover Wildlife, The New York Times, Popular Science, The Washington Post, Discover Magazine, New Scientist, and The Guardian, among many other sources.
July 12. 2024