A man stumbled upon an incredibly rare find while walking through a forest with his girlfriend and has left dozens in awe after sharing it online.
The New York man was strolling through The Finger Lakes region in the US state, and a fossil — potentially 325 million years old — in the creek bed caught his eye.
"A fossil I found in a creek bed while hiking through the woods with my girlfriend. Was scanning the water and seen a sun which caught my eye," he wrote alongside a photo of his discovery.
Despite "always looking at everything" on the lookout for something rare, it's his first time ever finding a fossil, he revealed.
At first glance the humble rock appears no different to any other, but a closer look would reveal some unusual markings.
Although he had no idea what it could be, some Facebook users had a go at guessing.
"What is it? A plant of sorts?" one questioned.
"Some sort of echinoderm I think," another said,
"Looks like a footprint of a bird or lizard," a third suggested.
While a fourth concluded it was a "crinoid fossil", and another agreed.
Fossil mystery solved: '200-325 million years old'
Geoscience Australia, an official government agency, said the fossil is "probably an echinoderm, and most likely a crinoid", a subset of echinoderms.
"Echinoderms are the animal group that includes starfish, brittle-stars, sea urchins, sea-slugs as well as crinoids," a spokesperson told Yahoo News Australia, and based on where it was found, this particular fossil could be up to 325 million years old.
"The rocks of the Finger Lakes region of New York state were formed under the sea, about 325-200 million years ago, which tallies with this specimen being the fossil of a marine creature," they said.
But echinoderms in general first appeared in the Cambrian Period (540 million years ago) and "are still with us today".
Despite being a marine animal, crinoids are often called ‘sea-lillies’, the spokesperson explained.
"They have a cup-like body, surrounded by many feathery arms that sweep food particles from the seawater into their mouth," the spokesperson told Yahoo.
"In many of the earlier crinoids, a long stalk elevated the body and feathery arms higher in the water column to access food better. They are much less common now than they were in the distant past."
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