- The very large mysterious "monster" lived near Cincinnati 450 million years ago.
- Scientists are starting to believe it's some sort of microbial structure.
- The beast may have been a mat or membrane made up of algae or bacteria that captured dirt and debris.
Is it animal, vegetable or mineral -- or something else entirely?
The collective brainpower of several dozen scientists was unable to unravel the mystery of a strange beast nearly half a billion years old, tentatively nicknamed "Godzillus."
Ron Fine, an amateur paleontologist from Dayton, Ohio, hoped the supersmart group of scientists at a regional meeting of the Geological Society of America could help explain the baffling find he made recently: the fossil of a very large, very mysterious "monster" that lived near Cincinnati 450 million years ago.
Unfortunately, the sea beast of Cincinnati had them scratching their heads, too.
"Everybody else was just as puzzled as we are -- and personally, I think that's pretty awesome," Fine told FoxNews.com.
He found the fossilized specimen last summer, a roughly elliptical shape with multiple lobes totaling almost 7 feet in length. It dates from almost half a billion years ago, when a shallow sea covered Cincinnati.
And despite its size, no one has ever found a fossil of this "monster" until its discovery by the amateur paleontologist last year.
But neither Fine nor the other members of the Dry Dredgers, an association of amateur paleontologists based at the University of Cincinnati that has a long history of collaborating with professional scientists, could explain what it is.
"We all have a theory, that's the problem! We're considering both animal and plant," Fine told FoxNews.com. "We know it's a fossil, something that was alive. But it's so different than anything else, we can't tell if it's animal or plant."
David L. Meyer of the University of Cincinnati geology department -- and co-author of "A Sea without Fish: Life in the Ordovician Sea of the Cincinnati Region" -- is able to whittle it down a little, though he remains just as baffled.
"In general, we're heading toward this being some sort of microbial structure that was preserved on the sea bottom, and it preserved some unusual patterns in the rock," he told FoxNews.com.
In other words, the fossil wasn't some ancient turtle, shark or other beast with fins and jaws and a tail. It was a mat or membrane made up of algae or bacteria that somehow captured enough dirt and debris that it could form into an unusual fossil.
"It's not the kind of thing that you would expect to fossilize," Meyer admitted. But there is a precedent in modern times: Microbes in the oceans today form such mats, he said.
"We know that microbial organisms in modern seas do kind of similar things," Meyer said. Not all fossils are the remains of creatures, he explained. Scientists often discover burrows, tracks trails and other trace evidence of prehistoric activity, he said.
Yet a positive explanation for the mystery sea beast remains a challenge. Fine plans to visit the Cincinnati Gem and Mineral Show this weekend at Cincinnati Gardens, a collaborative event held by the Dry Dredgers and the Cincinnati Mineral Society.
"I'll be there all day Sunday -- there's a possibility an expert might see it there," he said.
Meyer plans to go after the fossil through microscope, X-ray beam and geochemical analysis. And he may attend a larger Autumn meeting of the Geological Society of America, where the collective brainpower of several thousand scientists could solve the puzzle.
"We've had a couple hundred years of study of the fossils and rocks around here and still new stuff keeps coming up," Meyer said.