# Left in the Arctic: How an Abandoned Fossil Turned Out to Be a Giant Predator *A fossil first found in 1948 and left exposed for decades is revealed to be a new giant species at the base of the plagiosaurid family tree* By Sandee Oster · Published 12 August 2026 · Updated 15 August 2026 Source: https://archaeologyteahouse.com/stories/left-in-the-arctic-how-an-abandoned-fossil-turned-out-to-be-a-giant-predator --- ![q](https://archaeologyteahouse.com/media/01a00684-a47f-74ac-bf19-5853d797ac9b/1600.webp) *A. urdensis size comparison. Credit: Joschua Knuppe and A. urdensis reconstruction from Schoch et al. 2026* Have you ever heard of plagiosaurids? No, well, they are an ancient amphibian-like creature that looks a bit like if a frog and an axolotl had a baby. They are typically rather flat-bodied, with heads that look like half-moons. Most plagiosaurids were bottom-dwellers, not too large; they enjoyed spending their days lying at the bottom of water bodies, waiting to suck up their next bit of prey. But a recent study published in Papers in Palaeontology reports on a plagiosaurid unlike any other. First discovered in 1948, the specimen lay unprotected and unexcavated for decades before someone stumbled upon it again and excavated it. Again, decades would pass before the specimen was given a closer look, revealing that this plagiosaur was unlike any other. At over 2 meters long, it was a giant, and quite possibly a top predator. ### An Ancient Amphibian-Like Creature ![Arctic 2](https://archaeologyteahouse.com/media/01a00682-9765-77cf-b94c-3e4c0692154b/1600.webp) *Location of Bjørnøya (Bear Island) in the Arctic (A), a close-up of the discovery site on Urd peak (B), the local rock layers (C), and east coast of Bjørnøya with the site in the background (D). Credit: Schoch et al. 2026* Plagiosaurids were a strange group of ancient amphibian-like animals (temnospondyls) that lived during the Triassic period (~251 to 201 million years ago). What really set them apart was their bizarre body shape, with extremely wide, flat skulls atop flattened bodies, making them well-suited to life at the bottom of lakes, rivers, and seas. They personally remind me of the local South African Platanna frogs, flat-bodied, I believe, bottom-dwelling, amphibians that would sometimes find their way into our pool. They were an absolute pain to catch, their flat bodies making it almost impossible to grab them off the pool floor, and on top of that, they were seriously fast. Unlike the Platanna, the plagiosaurids had wide, flat mouths lined with rows of tiny teeth, suggesting they fed not by actively hunting but rather by sucking up their prey. Some species developed heavy armor, which not only protected them but also weighed them down, firmly anchoring them to the bottom of their watery homes. Fossils of these creatures have been found across the ancient world from Early Triassic Australia and Brazil to Middle Triassic Central Europe, Antarctica, and Late Triassic China, Thailand, Sweden, and Greenland. Regardless of where they came from, their fossils all suggest the same thing: they were extremely flexible, living in fast-flowing river channels, still freshwater lakes, and salty coastal lagoons. Interestingly, they are also famous for showing perhaps one of the most extreme cases of evolutionary stasis in amphibians, their overall body plan barely changing over the course of nearly 40 million years across European basins. I guess if it ain’t broke, don’t fix it. For the most part, these guys filled secondary ecological niches, leaving the role of top predator to other larger creatures such as the 3 to 5 meter-long crocodile-like capitosaurs and metoposaurids. But I guess every family has that one weird cousin who doesn’t follow the rules. And in the case of plagiosaurids, this cousin was *Arctobatrachus urdensis*. ### A Bear-Amphibian ![Arctic 3](https://archaeologyteahouse.com/media/01a0067e-fe6b-7fe9-b991-ccb2c0e2b4fd/1600.webp) *Arctobatrachus urdensis fossil: the skull and skeleton in 1948 (A–C), the skull today (D), and a reconstructed drawing combining the 1948 photos with the surviving remains (E). Scale bar = 10 cm. Credit: Schoch et al. 2026* The story of its discovery is a strange one. Back in 1948, during a British expedition, students from a joint Cambridge and Leicester expedition stumbled upon the poorly preserved remains of an enormous fossil on Bear Island (Bjørnøya) in the western Barents Sea. The crumbly old fossil was poorly preserved, and the discoverers lacked the means to excavate such a large specimen, so they collected a few fragments and took some photographs before going on their merry way. A field report by Jack Lowy would describe the fossil as around 2.6m long. The fossil and an image of it were briefly described by British paleontologist Alec Panchen in 1959, but no one returned to excavate it. And so it lay, battered by Arctic winds and rain, for decades to come, until, by chance, another expedition rediscovered the fossil in 1984. Time had taken its toll, and much of the already fragile fossil had crumbled away. Yet the team excavated it anyway. Again, it lay around for a while, receiving little attention, before it was fully prepared in the Stuttgart Natural History Museum for this study. Today, the fossil consists of three large blocks of rock, layered and scattered with bones, held together by a silicone mold. What survives are a skull, trunk, shoulder region, and about 45 cm of tail. ### A New Member of the Family ![Arctic 4](https://archaeologyteahouse.com/media/01a00680-1101-726a-97de-29407341577b/1600.webp) **Arctobatrachus urdensis* (A), *Gerrothorax pulcherrimus* (B), *Plagiosternum granulosum* (C), *Plagiosuchus pustuliferus* (D), and *Megalophthalma ockerti* (E). Scale bar = 5 cm. Credit: Schoch et al. 2026* Researchers analyzed the remains alongside the black and white photographs, ran their data through a phylogenetic analysis, and discovered the beaten-up specimen was a brand new genus and species. They named it *Arctobatrachus urdensis*. The name creatively weaves together the Greek word for ‘bear’ (*arctos*), a nod to Bear Island, and ‘amphibian’ (*batrachos*). Its species name, urdensis, came from the mountain peak on which it was found. Miseryfjellet mountain has three peaks, each named after one of the Norse norns (goddesses of destiny), Urd, Skuld, and Verdandi. *A. urdensis* was found on Urd Peak. The fossil was around 2.7 m long, with a skull forming an almost perfect semi-circle roughly 21 cm long and a whopping 70 cm wide. Based on the phylogenetic analysis, *A. urdensis* evolved at the base of the plagiosaurid family tree, making it one of the most primitive and earliest branching members of the group. Like most primitive plagiosaurids, *A. urdensis *and a close cousin, *Plagiosuchus pustuliferus*, share a set of ancestral traits that hint at how the whole family got its start. They had bodies and skulls that were relatively flat, hinting at a life that leaned toward bottom-dwelling; their ribs were long and curved more than later members; and they had well-developed throat skeletons suited for snapping open their mouths to suck in prey. What made *A. urdensis* different was its huge size, big teeth, long tooth rows, and unusually wide gape, all pointing to life as an active hunter. It is likely these giants were not filling some secondary niche but may have muscled their way into the ecological roles usually filled by giant capitosaurs and metoposaurids. Its giant trunk and tail also suggested they were more active swimmers, undulating their bodies as they propelled themselves through the water compared to their flatter, more sedentary descendants. Based on where they were found, in plant-rich, shallow marine settings, they were well-suited to live in or near coastal habitats similar to some of their other saltwater-dwelling relatives, such as *Plagiosternum *and *Gerrothorax*. They may have been a factor that helped them spread so widely across the ancient supercontinent Pangaea. --- In a recent study, researchers have finally given a long-neglected fossil the attention it deserves. Found nearly 80 years ago on a remote Arctic island, the fossil lay alone, its only companion the arctic winds that beat down upon it. Decades later, having survived brutal winters and freezing rains, it was excavated, before finally being analyzed, revealing not just a new genus and species, but a plagiosaurid unlike any other. *A. urdensis* was a giant, top predator sitting at the very base of the plagiosaurid family tree. It offers a rare window into the group’s early days and perhaps shows that even the most battered and beaten fossil can hold a wealth of knowledge. I wonder how many ancient fossils were left behind by discoverers simply because they did not have the means to extract them. Why do you think *A. urdensis* grew to such sizes, and why was it possibly the top predator in these waters? ### Reference Schoch, R.R., Chakravorti, S., Witzmann, F. and Lindemann, F.-J. (2026), A giant plagiosaurid temnospondyl from Bjørnøya (Svalbard, Norway) and the origin of the plagiosaurid body plan. Pap Palaeontol, 12: e70115. [https://doi.org/10.1002/spp2.70115](https://doi.org/10.1002/spp2.70115)