A somewhat silly-looking and pretty mysterious prehistoric creature, known as the Tully Monster, has confounded paleontologists for over half a century. The small creature, about a foot long, lived in the ocean and had a long, trunk-like extension from its body with a mouth and teeth. Its eyes, however, were much further back and set on either side of a rigid bar. They lived about 300 million years ago, and while there are samples from about 2,000 different individuals, it’s only ever been found in one Illinois coal mining site.
The creature was discovered by amateur paleontologist Francis Tully—hence the name—and it has been the Illinois state fossil since 1989. It has something of a fan club of admirers, but until recently, we didn’t even know what kind of an animal it was. Now, thanks to new research and the application of more modern analytical techniques, we know a few more things about it.
The creature, which was most likely a predator based on its mouth and teeth, had gills and a notochord, a sort of rudimentary spinal cord. Both those features were undiscovered until recently, which helps us figure out more or less where it features. Although there are a lot of differences that developed in the 300 million year since these creatures were fossilized, they seem to be related to modern lampreys.
Even with this knowledge though, we still don’t know when it evolved or when it went extinct, because the only fossils come from this one site. So we’re not sure when it entered the fossil record, or when it left, just that it existed around 300 millions years ago. Maybe they only lived in this one area, or maybe they were only rarely captured in the fossil record. Maybe we’ll learn more in the future, and maybe we won’t. At any rate, the Tully Monster remains a fascinating, albeit weird creature.