'Tully monster' mystery is far from solved, group argues

Date: February 20, 2017

Source: University of Pennsylvania

Last year, headlines in The New York Times, The Atlantic, Scientific American and other outlets declared that a decades-old paleontological mystery had been solved. The "Tully monster," an ancient animal that had long defied classification, was in fact a vertebrate, two groups of scientists claimed. Specifically, it seemed to be a type of fish called a lamprey.

The problem with this resolution? According to a group of paleobiologists led by the University of Pennsylvania's Lauren Sallan, it's plain wrong.

"This animal doesn't fit easy classification because it's so weird," said Sallan, an assistant professor in Penn's School of Arts & Sciences' Department of Earth and Environmental Science. "It has these eyes that are on stalks and it has this pincer at the end of a long proboscis and there's even disagreement about which way is up. But the last thing that the Tully monster could be is a fish."

In a new report in the journal Palaeontology, Sallan and colleagues argue that the two papers that seemingly settled the Tully monster debate are flawed, failing to definitively classify it as a vertebrate. The mystery of the Tully monster, known to scientists as Tullimonstrum gregarium, remains.

"It's important to incorporate all lines of evidence when considering enigmatic fossils: anatomical, preservational and comparative," said Sam Giles, a junior research fellow at the University of Oxford and coauthor of the study. "Applying that standard to the Tully monster argues strongly against a vertebrate identity."

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Scientists solve the mystery of the Tully Monster

MARCH 16, 2016

by Brett Smith

After baffling paleontologists for more than 55 years, a fossil enigma known as the Tully Monster has finally been definitively identified in a new report published in the journal Nature.

A relative of the modern-day lamprey, the Tully Monster is an oddly constructed sea creature with teeth at the end of a slender, trunk-like extension of its head and eyes that sit on both sides of a long, stiff bar.

In the study, paleontologists has established the 300-million-year-old animal, which grew just a foot long, was a vertebrate, with gills and a stiff notochord, which supported its body-- characteristics that weren't previously known.

"I was first intrigued by the mystery of the Tully Monster. With all of the exceptional fossils, we had a very clear picture of what it looked like, but no clear picture of what it was," study author Victoria McCoy, a graduate researcher at Yale University, said in a press release.

Uncovering the mystery of the Tully Monster

Discovered in 1958 and described in 1966, the Tully Monster has never been identified down to the phylum level until this latest research effort.

The species is named after amateur fossil hunter Francis Tully, the man who discovered the first specimen. Tully found the fossil in the coal-mining pits of northeastern Illinois, and thousands of other specimens were later discovered in the same location.

Since its discovery, the Tully Monster has achieved cult celebrity status in Illinois and it became the official state fossil in 1989.

"Basically, nobody knew what it was," said study author Derek Briggs, curator of invertebrate paleontology at the Yale Peabody Museum of Natural History. "The fossils are not easy to interpret, and they vary quite a bit. Some people thought it might be this bizarre, swimming mollusk. We decided to throw every possible analytical technique at it."

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