The ‘Tully Monster’ ( Tullimonstrum gregarium ) is a species of underwater slug with two antennae crowned by eyes and a long trunk that ends in a mouth full of sharp teeth. We know that this strange alien-looking sea monster inhabited the depths of the Earth about 300 million years ago in the waters that currently make up the state of Illinois (USA). There are thousands of fossils ; all of them belong to a formation called Mazon Creek but, despite numerous investigations, scientists could not reach a consensus regarding its spine.
Since its fossils were first unearthed in 1958, the “Tully Monster” has therefore defied classification. This strange, narrow-necked, log-like creature swam with cuttlefish-like fins located in the tail section. Needless to say, it looked more like a chimera or fake than any kind of real creature. It is clear that it was very different from any other animal that has been found on Earth. Yet it is.
Now, a new study published in the journal Geobiology conducted by a team of researchers affiliated with various institutions in the US and Germany has found evidence suggesting that the Tully monster was a vertebrate. In their article, the group describes their work on Raman microspectroscopy of ancient creatures and what they learned about them.
A vertebrate, of which its closest living relative is probably is a lamprey. Careful, high-tech analysis of the fossils established that the Tully Monster had gills and a rigid rod or notochord (basically a rudimentary backbone) that supported its body.
How have they come to this conclusion?
Rather than trying to find out if the Tully monster was a true vertebrate by doing anatomical studies, the researchers chose to approach the problem from a chemical perspective. They noted that invertebrates have chitin in their toughest tissues that helps them maintain their shape: chitin is made of long chains of sugar molecules. In contrast, vertebrates have certain types of proteins and keratin that make up the collagen found in animals with back bones.
Analysis of samples showed evidence that the types of proteins and keratins in the Tully Monster fossil remains were representative of vertebrates. These findings therefore suggest that it was a vertebrate, although scientists acknowledge that more research is required to make a final confirmation.
Of course, despite his recreation being quite terrifying – his teeth do not help much – the largest Tully Monster that has been found is barely 30 centimeters long.
“It is so different from its modern relatives that we do not know much about how it lived,” said Victoria McCoy, leader of the first published work on this creature in 2016. “It has large eyes and many teeth, so it was probably a predator. ” .
Referencia: Victoria E. McCoy et al. Chemical signatures of soft tissues distinguish between vertebrates and invertebrates from the Carboniferous Mazon Creek Lagerstätte of Illinois, Geobiology (2020). DOI: 10.1111/gbi.12397
