The Tully Monster is an Extinct Species of…

Since the Tully Monster is not a living creature, it is not technically "living" anyplace on the planet. However, the ruins of this peculiar prehistoric life form can only be found in one location, and no one is really sure what it was. The Tully Monster, also known as Tullimonstrum gregarium, was an aquatic creature, and fossils have allowed us to reconstruct its appearance. You'd think that would be sufficient evidence to conclude that it was a fish, crab, or other creature, but that is not the case. It had no backbone and a mushy body. Although there is some disagreement about that. It had a segmented, tapering body.

Its body culminated at one end in a tiny mouth with eight teeth that resembled more of a tentacle than anything else. The other had a finned tail. Additionally, it possessed two eye stalks that extended about a third of the way down its body from its tiny mouth.

Despite having a soft body, the seas it resided in were ideal for keeping the bodies in the mud and letting us see what they looked like. And only Mazon Creek, Illinois, contains those unique fossils. People don't currently have any proof that they lived somewhere else, if they did. But perhaps that's for the best given people are not even sure what kind of creature it might have been—let alone whether it had a spine or not.

Kingdom: Animalia
Subkingdom: Eumetazoa
Clade: ParaHoxozoa
Clade: Bilateria
Clade: incertae sedis
Genus: †Tullimonstrum