A giant salamander—and by “giant” I mean about 2.5-4 meters long—equipped with teeth and wicked fangs was found in Namibia, dated at about 270 million years ago, and just reported in Nature. Its significance is that it is early, but is considered a “stem” tetrapod, meaning that it has some of the characteristics of modern amphibians, which are tetrapods (four-legged animals that could move around on land). The authors, according to this CBS News story, suremise that it “was considerably longer than a person, and it probably hung out near the bottom of swamps and lakes”. It was also an apex predator, meaning that it ate other animals, but there was nothing around that could eat it.
Its was found in an area that, 270 million years ago, was at high latitude, ergo cold and partly glaciated. This beast is the first suggestion that there was a tetrapod fauna in cold-ish climates at that time.
Click below to see the article, or download the pdf here:
The researchers recovered a skull that was about 60 cm (2 feet long), as well as the front part of the postcranial skeleton. The authors don’t give a size estimate, but with a two-foot head it was probably large, and could have been 12 feet long: the longest salamander known yet. (The largest living salamander, the Japanese giant salamander (Andrias japonicus), can attain a length of about 5 feet. This puppy could have been twice as long.
Two skull fragments were known of this animal before, but it hadn’t been named and there were no remains of the skeleton. The authors named this one Gaiasia jennyae, after the Gai-As formation in which it was found, and also after Jenny Clack (1947-2020), who studied early tetrapods. (This, of course, will anger the pecksniffs who think that animals shouldn’t be named after people, but they can jump in the lake.) It is the only species in the genus Gaiasia.
The sample in the field (from the Supplementary information):
Here’s the skull in dorsal (a,b) and ventral (c,d) views, and reconstructions.
And a reconstruction of the skull and postcranial skeleton they found. Because we don’t have the posterior skeleton, length estimates are guesses.
Here are photos and a reconstruction of the lower jaw. The white circles show the fangs, which are indicated in the upper drawing. There were three on each side, and interlocking fangs on the top mandible as well. It ate by both suction and biting:
. . . and a reconstruction of the front of the animal from the paper. Remember, that fearsome head was about two feet long!
Now this is unlikely to be any kind of ancestor of reptiles, but it’s likely that this is one of several species occurring when tetrapods had already evolved from fish and one of its relatives probably gave rise to modern amphibians, while another gave rise to all modern reptiles (and after followed the evolution of birds and mammals). Its importance is not only the “gee whiz” factor, but also the indication that there was a thriving ecosystem at high latitudes about 270 myr ago. After all, this is an apex predator, and it had to eat something aquatic (fish or, perhaps, other early amphibians). So if these creatures existed, there must also have been many other animals living at high latitudes at that time.
Credit: Source link