A pair of Calgary fishermen who came across the biggest catch they ever caught on Castle River this summer are now sharing their story about how they came across their find.

Evan and Jared Cappon were at their favourite fishing spot on Castle River when 14-year-old Jared spotted something unusual in the water.

“I went up stream a bit to scout it out and look over and there's a rock with a tire track on it, thought it was pretty cool, walked by it, and on the way back looked a little closer, and realized it was a spine and not a tire track, and a skull on it too which was really awesome,” says the teen.

Evan said that when he saw it, he was sure it was an animal, but it wasn’t at all what he was expecting.

The fishermen then attempted to lift the rock themselves, but it was far too much for them to handle and that’s when they called the Royal Tyrrell Museum in Drumheller.

A team was then dispatched with a helicopter to remove the boulder and transport it back to Drumheller for examination.

Early findings show the fossil was embedded in the rock in three dimensions instead of being flattened by 80 million years of compression.

Donald Henderson, with the museum, says the shape of the rock is also telling. “The roundness of the boulder tells us it’s been rolling along the river for a long time, years and years, but I think what the flooding did – the high water levels – it pushed it and rolled it so they could actually see something.”

Officials say the fossil is a hadrosaur, and it’s the first time that a dinosaur of this type has been found in the Pincher Creek area of southern Alberta. They say the species also unknown, so it will also need a name.

Henderson says the Cappons may even be included in the decision process. “The person describing it gets to name it. We’ll probably work the locality name in, or the people who found it, or something like that.”

The hard work ahead includes slowing chipping the rock away from the fossil to expose as much as they can. The arduous work could take upwards of two years.