This dinosaur tooth, which can fit in a man's hand, was found last week during the excavation of a tunnel in west Edmonton. (Province of Alberta)Aaron Krywiak was scratching at dirt in a sewer tunnel nearly 30 metres below a suburban Edmonton neighbourhood on Thursday when his hands ran over something unusual.

"I noticed an interesting-shaped rock," Krywiak, a City of Edmonton employee, said in an interview Monday.

Krywiak passed the object to co-worker Ryley Paul, who was pretty sure it was a dinosaur tooth.

"I was pretty giddy because I loved dinosaurs as a kid." Paul said. "So just being able to hold the bone was pretty intense."

Aaron Krywiak was at work for the City of Edmonton when he found the dinosaur tooth Thursday. (CBC)After Krywiak and Paul showed their foreman their discovery, police were called to rule out the possibility they'd unearthed human remains.

In fact, the young men had found what turned into a motherlode of dinosaur bones — parts of a large limb bone from a dinosaur known as Edmontosaurus, and the tooth of a tyrannosaurid, which was likely from an Albertosaurus.

"I'm thrilled," Krywiak said. "I never thought I'd ever get a chance to do something like this, so it's something new for me. It's really, really exciting. I'm just enjoying every minute of it."

The Royal Tyrrell Museum, known for its expertise in paleontology, said the find in the Quesnell Heights neighbourhood was significant.

"The discovery is significant for its location," said Don Brinkman, the museum's director of preservation and research. "The animals are well-known but what this does is put those animals in a particular association in a particular place."

Ryley Paul said he felt giddy when he held a dinosaur bone in his hand. (CBC)After police looked at Krywiak and Paul's find, the city called Jack Brink, curator of archaeology at the Royal Alberta Museum, who then contacted Mike Burns, a PhD student in paleontology at the University of Alberta, to confirm the objects were fossils.

They unearthed more bones from the site.

Brinkman commended the city workers for leading researchers to this find.

"Kudos to the people doing the excavation that they recognized that this was something unusual," he said.

The bones will be dug up over the next couple of days and taken to the Royal Tyrell Museum in Drumheller, Alta., for examination.