With this picture we continue the coverage of the jawless fish, though admittedly this is probably going to be the most contentious of all the entries which is consistent with the second part of the last series I did on cephalopods strangely enough.

Tullimonstrum gregarium also known as The Tully Monster of Tully's Monster. It dates quite late for such an oddball to the Moscovian stage of the Pennsylvanian (also called the Late Carboniferous) 309 mya or so in the amazing Mazon Creek formation in what is now Illinois famous for the preservation of a lot of soft tissues and rare animals. It gets it's name for it's very monstrous appearance that confounds paleontologists. It has a general body plan of an early stem fish, long snail like eye stalks with camera eyes similar to those of vertebrates and a long proboscis with a set of pincers with 8 teeth on each half. It would have used this to grab prey to eat as a necktonic predator. Note these are not true jaws as we understand it which are derived from gill arches but an entirely independent structure so it still counts as jawless.
But does it count as a "fish" well that's the contention with this animal you see it's been heavily debated to being either a mollusk, a arthropod, perhaps being a conodont, some worm, a tunicate, or a vertebrate. The current consensus which will no doubt change in the future holds that it is likely a non-vertebrate chordate due to the presence of what is thought to be a notochord. Meaning it would be most related if very distant to something akin to what we met yesterday. This is still highly aberrant and regardless of it's taxonomic placement was really one of the last Cambrian oddballs.