(CNN) -- It's like a scene out of a Flintstones comic. Fred is running a backhoe and drops its shovel right on top of a dinosaur's tail.
It happened in Canada this week when the backhoe laid bare an extremely rare find, the fossil of a dinosaur millions of years old.
A whole 35-foot dinosaur may be slumbering inside the rock a construction worker hit while clearing a site in the town of Spirit River. He was making way for an oil pipeline.
The company stopped work and called around to find someone who knew something about dinosaurs.
Word got to paleontologist Matthew Vavrek, who went out to inspect. He wasn't expecting to see what he found on the side of a sandstone boulder.
"As we walked around it, we saw this whole part of a tail of a dinosaur. To see something like that is pretty incredible," he said.
Paleontologists usually find fossils jumbled up, broken apart, crushed and spread out over a large area, not in one piece like this one.
"The last time I've seen something like that was in a museum. I've never found something like this before," he said. He has rarely ever even heard of a find like this anywhere in the world.
Had the backhoe kept going, this fossil would have turned to mush, too.
The chunks that the shovel picked up, quickly fell to pieces. The driver noticed this and immediately halted it.
The dinosaur may have been tough when it was alive, but its fossil is as fragile as crumb cake.
"You handle it carefully, or it's just going to shatter," Vavrek said.
The Tourmaline Oil Corp has enlisted its workers and machinery to help Vavrek and his colleagues remove it gingerly and slowly.
That could take weeks, if the weather holds, or months, if there is a cold snap that freezes the dino in the ground.
The first flakes have already fallen, Vavrek said. Workers are in a race to beat Alberta's usually heavy snow fall.
As they go, they will reveal just how big of a find this is.
"We don't know for sure that the rest of the animal is there," Vavrek said. "Sometimes, all you get is what you see."
They will take it out surrounded by much of the soil it's buried in then cart it off to a place where they can slowly clean and prepare it for study and identification.
Technicians will use tiny jackhammer-like instruments to buzz away the dirt and reveal the stony skeleton.
But even then, they still might not know what kind of dinosaur it is. If it is a textbook specimen that scientists are already familiar with, it could take years to categorize it.
"If it turns out to be something new, never found before ... it would take even longer," Vavrek said.
If they do pull a whole dinosaur out of the ground, Vavrek thinks it will be about mid-size as dinosaurs go, or a little larger.
Its happenstance discovery by a backhoe seems ironic to Vavrek.
He is used to grueling prospecting tours for much smaller fossils in the Alberta wilderness, where he has to keep an eye out for dangerous wild animals.
He has had some encounters with black bears and grizzly bears. But they've gone well so far.
CNN's Dave Alsup contributed to this report