The Triassic Giant Predator: Arctobatrachus urdensis

Publication Info:

Transcript:

Rainer R. Schoch et al, A giant plagiosaurid temnospondyl from Bjørnøya (Svalbard, Norway) and the origin of the plagiosaurid body plan, Papers in Palaeontology (2026). DOI: 10.1002/spp2.70115

Meet Arctobatrachus urdensis, the brand new giant Triassic plagiosaurid. This giant predator was just named from fossils lost at the top of an arctic mountain 80 years ago!

Episode 324

Notes:

A brand new giant Triassic predator was just named from a fossil that's been waiting to get picked up from the top of a mountain for 80 years. And yes, it's just as dramatic as it sounds. Plagiosaurs were a group of amphibians that lived in the Triassic roughly 201 to 251 million years ago. Picture a kind of giant wide flat salamander with an even wider and flatter head. Their heads were literally usually wider than they were long. This is Arctobatrachus urdensis and its remains were originally discovered in the Arctic almost 80 years ago. Unfortunately, at the time all they could do was take pictures. They couldn't actually collect the remains. And to be fair, it's a big animal with the skull alone being almost 28 inches wide and the entire animal being almost 9 ft long. Unfortunately, that means that this skull has been sitting on top of a mountain exposed to Arctic conditions for almost 80 years now, and that's not great for fossils. So now it's looking a little rough. But it was recently finally recovered, and luckily they had those original photographs to help reconstruct it. While there are other big plagiosaurs, Arctobatrachus does stand out because it's the biggest one ever discovered, having that 9-ft body length. And these were not lightly built animals, meaning that in the Triassic this animal would have probably terrorized shallow aquatic environments, just sitting flat on the bottom waiting to swallow whole anything that got too close. As usual, if you want more information, here's the source.