About three years ago, a curious 10-year-old boy was touring a Colombian monastery when he saw something unusual at his feet.

He spotted what looked like a fish in the flagstones, so he took a photo. A few days later, he brought that image to a nearby Paleontological Research Center, where scientists were able to say with certainty that the boy had stumbled upon a fossil. They notified their colleagues at the University of Alberta and, with combined research efforts from multiple sources, they figured out that the boy had discovered an ancient group of fish that had never before been recorded in the Americas.

"We see that the tropical region was this melting pot of creatures that lived there," says Oksana Vernygora, the PhD student who led the study. "We just need to go and explore."

View Images Two sides of the newly discovered fossil fish. The part and counter-part of the specimen that are preserved in what used to be flagstones in the monastery Courtesy Oksana Vernygora

The findings were published in the Journal of Systematic Palaeontology January 31.

The Road to Discovery

Located in the outskirts of Ráquira, Colombia, the Monastery of La Candelaria is about an hour's drive from the city. The 17th-century complex consists of a chapel, a small museum, a courtyard, and a cave that the Augustine monks who founded the monastery would have lived in. (Today, there's also a hotel for tourists.)

About two decades ago, construction began on the monastery's walkways, bringing in stones from a small Andean quarry in Boyacá, about half an hour away. The quarry had been specifically opened to mine material for construction projects, and it had been closed again right after the stones were extracted. The University of Alberta researchers were able to trace the stones back to that quarry.

"The fossil was completely out of context," says study co-author Javier Luque. "The quarry was unknown to us."

Now that there's paleontological interest in the stones from that quarry, researchers are being allowed in.

Finding "Lizard Fish"

The fish species is called Candelarihynchus padillai, named for the monastery where it was found and the Greek word for "nose." It's a slim, long-jawed, fine-toothed "lizard fish" measuring 16 inches long. The fish would have swum the fast-flowing waters of South America 90 million years ago during the Late Cretaceous Period, preying on small organisms like crustaceans, larvae, and mollusks.

The fish doesn't have a modern-day equivalent, but it would have been able to migrate long distances and looked somewhat similar to today's barracuda.

This is the first fossil of its kind to be spotted in South America, and it's almost perfectly intact. Since it's two-dimensional, the fossil stayed preserved for years while dozens of visitors stepped on the walkway it was a part of.

The South American fossil record is sparse and was previously restricted to only Brazil. More recent discoveries have turned up marine fossils in Argentina and other parts of Colombia.

This new find gives insight into how these fish were dispersed throughout the ocean. It could also provide clues for how the fish adjusted to a changing environment, which could be useful to predict how today's marine life will adapt to warming waters. (Watch: "99% of These Sea Turtles Are Turning Female—Here's Why")

"We're uncovering a new diversity in the tropics," Vernygora says.

Giving Back

Unfortunately, the researchers lost touch with the boy who found the fossil. They only have his name and email, but they're hoping that with the publication of the recent paper, he will come forward again so they can give him proper credit.

"It would be our pleasure to officially give him a copy of the article and just thank him in person for bringing to us such an amazing discovery," Luque says. "Sometimes it takes a little bit of curiosity and an inquiring mind."

And now that a new ancient fish species has been discovered, what's next for the researchers?