How forces of nature, luck led to discovery of 163M-year-old 'fish-lizard' in Utah

Alan Dailey, of Hooper, pictured with the block of sandstone with ichthyosaur fin, vertebrae and ribs just before a team collected the fossil from Flaming Gorge on Sept. 8. Dailey found the fossil while boating in May.

Alan Dailey, of Hooper, pictured with the block of sandstone with ichthyosaur fin, vertebrae and ribs just before a team collected the fossil from Flaming Gorge on Sept. 8. Dailey found the fossil while boating in May. (Utah State Parks)



Estimated read time: 4-5 minutes

VERNAL — Alan Dailey was boating at Flaming Gorge Reservoir in May when he stumbled upon something peculiar.

As the Hooper man stopped near the shoreline and looked out at the rocks in front of him, he noticed bones within a 400-pound sandstone block just barely sticking out of the water, about 50 to 80 feet away from the shoreline.

"It was basically at the top of the beach; so if the reservoir was full, this thing would have been right at the edge of the water," said John Foster, the curator at the Utah Field House of Natural History in Vernal.

Dailey took photos of the rock and quickly thought to send them and his GPS coordinates to James Kirkland, the state paleontologist for the Utah Geological Survey. That information was forwarded over to the Utah Field House of Natural History in Vernal, who eventually traveled out to the location to find whatever it was that caught Dailey's eye.

There, crews found a fossil with one front forefin, 19 articulated vertebrae and 10 ribs, according to Foster. Utah paleontologists reviewed the specimen and determined it was consistent with a unique prehistoric creature known as an ichthyosaur, a name that means "fish-lizard." The animal was essentially a fish-lizard combination that existed in the Late Jurassic epoch, about 163.5 to 145.5 million years ago.

"The ichthyosaurs looked more or less like a reptilian dolphin," Foster said. "They had the same short torpedo-shaped body, dorsal fins, pectoral and pelvic ends, a long snout with conical teeth for eating fish. The main difference was their tail was vertical rather than flat like a dolphin's is, and that just has to do with the different ways that mammals move compared to reptiles."

An artist depiction of what an ichthyosaur looked like. An Icthyosaur fossil found at Flaming Gorge in May is believed to be about 163 million years old.
An artist depiction of what an ichthyosaur looked like. An Icthyosaur fossil found at Flaming Gorge in May is believed to be about 163 million years old. (Photo: Utah State Parks)

The particular ichthyosaur discovered at Flaming Gorge is believed to be about 163 million years old. State crews were able to recover the fossil on Sept. 8 and it is currently being prepared at a lab in eastern Utah.

A lucky discovery

The fossil discovery was the result of two natural forces at play — with a pinch of luck. As a result of Utah's drought, Flaming Gorge wasn't at 100% capacity when it was found. If the reservoir was completely full, Dailey may never have come across the fossil when he did.

But unlike other recent drought-related reservoir discoveries, erosion was the primary reason for the discovery. Experts believe the 400-pound sandstone block fell a short distance into the water "relatively recently" from vertical-lying rocks above the water in the area it was discovered.

"As that sandstone weathered, this block basically fell down onto the beach from essentially a vertical position," Foster said, adding that it likely had only been visible for a short amount of time when Dailey discovered it.


You wouldn't have been able to see the fossils if it had landed facing the other way ... It landing (fossil) side-up was definitely a good thing.

–John Foster, Utah Field House of Natural History


How it landed in the water is a piece of luck that made Dailey's discovery happen. When it fell, the rock landed with the fossil facing outward. It made it possible for a boater to come across and see it.

"You wouldn't have been able to see the fossils if it had landed facing the other way," Foster said. "It's such a big block that nobody would have been able to flip this thing over and see, on the off chance, there might have been an ichthyosaur fin and vertebrae on the other side of it. It landing (fossil) side-up was definitely a good thing."

Crews unload the ichthyosaur block found in Flaming Gorge at the Lucerne Valley Marina near Manila, Daggett County, on Sept. 8, 2021.
Crews unload the ichthyosaur block found in Flaming Gorge at the Lucerne Valley Marina near Manila, Daggett County, on Sept. 8, 2021. (Photo: Utah State Parks)

Hauling it to the Utah Field House of Natural History took a bit of work. A crew of about a dozen workers — paleontologists, U.S. Forest Service employees, volunteers from the Utah Field House of Natural History and Dailey — were eventually able to wrestle the 400-pound sandstone block out of the water last month and back to shore, where a forklift was used to unload the rock from a boat to a truck.

How you can see the fossil

A team at the Utah Field House of Natural History is currently preparing the fossil so that it will eventually be on display at the Vernal museum. Visitors can see it being prepared in the facility's lab as a team prepares it for an exhibit, according to the museum.

While eastern Utah is known for dinosaur discoveries, the ichthyosaur fossil joins a 152 million-year-old log as recent fossil discoveries in the region have been taken to the Utah Field House of Natural History. Both of those findings predate most of the dinosaur bones that paleontologists have dug up.

Foster said the two recent findings help them better understand the entire environment that existed in the age of dinosaurs.

"The ichthyosaur reminds us there were seaways in the same region (as dinosaurs) and the ichthyosaur — even though it's a few million years older than the dinosaurs at Dinosaur National Monument — kind of shows that there were these marine reptiles that existed at the same time as the dinosaurs," he said. "They filled these ecological roles that are pretty similar to things being filled by mammals now."

Related Stories

SIGN UP FOR THE KSL.COM NEWSLETTER

Catch up on the top news and features from KSL.com, sent weekly.
By subscribing, you acknowledge and agree to KSL.com's Terms of Use and Privacy Policy.

KSL Weather Forecast