A Mexican paleontologist was cleaning up after lunch with a group of schoolchildren she'd been teaching to dig for bones in northeastern Mexico when she found the dinosaur bone.
"I was basically collecting trash," Martha Carolina Aguillon Martinez recalled at a news conference Tuesday.
Twelve years later, after much digging, drilling and piecing together, it became clear that the helmet-crested, duck-billed dinosaur didn't belong to any previously identified species. This was new.
The composition of its skull — with a nose on top of its head and elongated nasal passages — meant its call was probably one of its most unique aspects, said Terry Gates, a Utah Museum of Natural History paleontologist who was part of a team of Mexican, American and Canadian experts involved with the excavation.
"They were like little trumpeters," he said. "This is totally odd and freakish."
Members of the species could likely have grown to 30 or 35 feet long, Gates said.
The one recovered near Saltillo, the capital city of the Mexican state of Coahuila, was only about 25 feet because it died in adolescence, he said.
That would have put the species, named Velafrons coahuilensis, around the same size as the Tyrannosaurus rex — though it probably wasn't as vicious, being a plant eater.
Scientists have dated the fossil to about 72 million years ago, when much of eastern Mexico was still underwater.
"Velafrons was probably a beach bum," Gates said.
That could have contributed to its relatively short 10-million-year lifespan as a species, said Utah's state paleontologist Jim Kirkland, another expert involved with the project.
He said the species' tendency to live near areas where rivers met the sea could have made for a precarious situation.
Its habitat would have been susceptible to large storms in the same way the Mississippi River Delta was when it succumbed to disastrous effects during Hurricane Katrina in 2005, he said.
The scientists talked about the dinosaur find — which was published in the Journal of Veterbrate Paleontology in December — at a news conference at the University of Utah on Tuesday.
Researchers said the discovery helps fill in holes in the existing picture of the hadrosaur family, which could include as many as 10 varieties of duck-billed dinosaurs across North America.
"Up in Canada, there is a dinosaur very similar to this," Gates said.
He said that could suggest migration patterns over time.
Scott Sampson, research curator at the museum, said the discovery both answers existing questions and poses new ones.
"This has opened up a whole new window — but also a whole new mystery — into the world of dinosaurs, and we hope Mexico holds the answers," he said. "The reality is, we've just scratched the surface."
Sampson also said information about another new species from a nearby site — a relative of the triceratops — should be available this fall.