True nature of ‘Tully monster’ revealed

Ancient oddity is a lamprey ancestor

BY 
2:00PM, MARCH 16, 2016

If some of the most bizarre zoo animals merged into one cartoonish creature, it might look something like the “Tully monster.”
Fossils of Tullimonstrum gregarium, a soft-bodied animal that lived roughly 300 million years ago in what is now Illinois, feature wide-set eyes like a hammerhead shark, a nose like an elephant, and a mouth that could pass for a crab claw with teeth. It’s one of the “weird wonders” of its time, and for more than 50 years, it has stymied scientists debating its identity.
Now, an analysis of more than 1,200 museum specimens, reported March 16 in Nature, says the Tully monster was a vertebrate (not a slug, or a worm, or an arthropod). A long, thin tube running down the creature’s back, for example, was not part of the gut, as some scientists had suggested, but a notochord, a structural hallmark of vertebrates. 

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