A 12-year-old boy made the discovery of his lifetime when he discovered a dinosaur fossil dating back 69 million years.

An amateur palaeontologist was walking with his father in a fossil-rich part of Alberta, Canada this July, when he saw bones protruding out of a rock. On Thursday, the skeleton’s excavation was completed.

The kid, Nathan Hrushkin, says that when he first looked at the bones, he was “literally speechless.”

Nathan Hrushkin, 12, and his father, Dion, discovered the partially exposed bones while hiking with friends in Horseshoe Canyon near Drumheller, Alberta.

“He told the BBC, “I wasn’t even excited, even though I know I should have [been]. “I was in so much shock that I had actually found a dinosaur discovery.”

Nathan, who has been interested in dinosaurs since he was six, often goes hiking in the Nature Conservancy of Canada’s protected site in the Albertan Badlands with his father.

“I’ve always just been so fascinated with how their bones go from bones like ours to solid rock.”

A year ago, they had found small fragments of fossils, and his father guessed that they were falling down from the rock above. So this summer Nathan decided to inspect. The fossilised bones were poking out of the side of a hill.

“Dad, you got to get up here!” he called to his father.

His father knew Nathan had found something by the tone of his voice.

“They looked like bones made of stone – you could not mistake them for anything else,” his father, Dion Hrushkin, said.

“It looked like the end of a femur – it had that classic bone look to it – sticking straight out of the ground.”

The bones belong to a young hadrosaur and have been dated at around 69 million years old.

Nathan knows that the fossils are protected by law, so when they got home, he and his father logged in to the website for the Royal Tyrrell Museum, which is located in Alberta and devoted to the study of prehistoric life. The museum advised them to send photos of their discovery and its GPS coordinates, which they duly did.

The Badlands are home to many fossils, and a dinosaur – named the Albertosaurus – was discovered by Joseph Tyrell in the late 1800s. But the part of the conservation site where they were walking was not known for fossil discoveries, so the museum sent a team of experts to excavate.