Strange extinct creature resembling a giant salamander

The discovery in Namibia, Africa, of the fossil remains of a superpredator that in life must have measured about 4 meters long, that had enormous fangs, and that in some aspects resembled a giant salamander, is a surprise for the scientific community and calls into question various widely accepted hypotheses. The beast, which has been given the name Gaiasia jennyae, was one of the first tetrapods, four-legged animals that lived more than 280 million years ago.

The study was carried out by an international team led by Argentine paleontologist Claudia Marsicano and was published in the academic journal Nature.

For some time now, the classic story had not been convincing. The scientific explanations had gaps that she had doubts about. Some had been proposed at international conferences, but she needed proof, evidence of a remote past that occurred more than 280 million years ago. She travelled to the north of Brazil, and also to Namibia, and insisted for years on visiting an area of ​​the African desert that she always missed: Gai-as. Until, finally, she stopped there with her work group, in the middle of the desert nothingness, with tents, equipment and a water truck.

The landscape of that place is very similar to others, with outcrops that at first glance look like rocks that all look alike, but the keen eye of the team led by paleontologist Claudia Marsicano, from the University of Buenos Aires (UBA) in Argentina, focused on some pieces that caught their attention. They searched for more pieces and, little by little, the skeleton of an animal began to take shape: the Gaiasia jennyae. The beast had a large 60-centimeter skull and fearsome fangs, on a body about four meters long.

The find challenges currently accepted hypotheses about the early evolution of tetrapods.

The first observations of the extinct beast were disturbing. “This is very strange,” he said to himself. Because its general appearance was that of a more evolved animal, a temnospondyl amphibian, but different characteristics of the skull identified it with much more basal tetrapods that were not found in Pangea during the Permian. “Due to its characteristics, it was a mixture of very advanced things like a large predator that has fangs and gigantic teeth in the front part of its face and others that related it to tetrapods from the Northern Hemisphere from much older rocks,” he recalls. “I began to have a crisis.”

Artist’s impression of what a typical adult of the Gaiasia jennyae species would have looked like in life. (Illustration: Gabriel Lio)

Amid the confusion over the results of the first analyses, the COVID-19 pandemic struck, and his trips to observe the materials were interrupted. “I could only study the photos, my notes and drawings,” he says. Then, the second author of the work, Jason Pardo of the Field Museum of Natural History in Chicago, United States, joined the group and made the relevant comparisons.

“We concluded that this animal is about 280 million years old and is a close evolutionary relative of forms from the early Carboniferous. This, then, changes the story that assumes that these first tetrapods developed and diversified in what would be the Paleoecuador region during the Carboniferous, in tropical and subtropical zones. And that they then evolved and colonized colder areas at higher latitudes during the Permian,” he says.

In this case, the discovery shows a more primitive and more developed animal, in a place where it should have arrived fifty million years later, according to current hypotheses. “I always felt that the story of how the first tetrapods had diversified in the Paleozoic was not as simple as it was said,” he recalls, and then adds: “After this discovery there is a different story, much more complex.”

Regarding the name given to the new species, the first part, Gaiasia, refers to the Gai-as formation where the remains were found. The second part, jennyae, is in honour of Jenny Clack (1947–2020). “An incredible woman, a palaeontologist, professor at the University of Cambridge and in charge of the Vertebrate Palaeontology collections at the museum of the same university,” explains Marsicano, with emotion.

Deep and varied feelings have been running through her since she found out that her work would be published in Nature. “I am the first woman in Argentina, in Paleontology and Earth Sciences, to publish as first author in this journal,” she stresses with joy, while she waits with anticipation to obtain funding to return to carry out paleontological excavations in Africa.

“There is a lot of material to study, some pieces we collected and others are still in the field. In addition, I have already detected that there are more taxa of tetrapods and even fish, very different in the few fragments that I have been able to identify, that is, it is not only this animal, but in that package of rock from the Early Permian of Namibia there is a new fauna and that is what we want to investigate in the future,” she concludes enthusiastically. (Source: Cecilia Draghi / NEXciencia / University of Buenos Aires. CC BY 3.0 Deed)