The Unnamed Japanese Iguanodon

Publication Info:

Transcript:

Masami Kondo et al. 2026. An iguanodontian sternal plate from the Upper Cretaceous Ashizawa Formation (Futaba Group) of Fukushima Prefecture, Japan. Paleontological Research 30: 122-134; doi: 10.2517/prpsj.250042

It may not have a name yet, but this new dinosaur from Japan could be changing everything paleontologists know about Iguanodon relatives from far eastern Laurasia!

Episode 331

Notes:

New dinosaur just dropped. So, I know you probably know what an Iguanodon is. The name's been around for like 200 years. It was literally the second dinosaur ever named right after Megalosaurus. Well, Iguanodon and its close ornithopod relatives are all in the family Iguanodontia, and that also includes a lot of the famous duck-billed dinosaurs. And they're a crazy diverse group. Just size alone, they can be anywhere from like 6 ft to 30 ft plus. This hatchet-shaped bone was originally discovered in 1999 in Cretaceous deposits in Japan dating back to about 90 million years ago. And it's been kind of just sitting unstudied since. But, luckily, after 30 years, paleontologists just looked at it, and they were able to mostly identify it. According to paleontologists, this is the right sternal plate of a relatively small, like 10-ft-long Iguanodontian. Currently being labeled as an indeterminate Styrax sternum. At least in this case, it looks like it's consistent My light just caught on fire, so this video's going to be a little darker from here on out. Uh it's much more consistent with a later, more derived Iguanodontian. And what's now Japan was the furthest east part of Laurasia, meaning that even pretty far away from the bulk of their relatives, Iguanodontians were still a pretty diverse group. As usual, if you want more information, here's the source.