A team of paleontologists in southern Colorado has unearthed two enormous fossils, a tibia and fibula, belonging to a longneck sauropod dinosaur that roamed the earth millions of year ago.

The fossils come from the Royal George Region, an area “famous for the discovery of a wide variety of prehistoric fossil remains,” per Cañon City officials.

In a Facebook post detailing the impressive find, Cañon City and the Royal George Regional History Museum revealed that the fossils weren’t originally discovered by professionals. Instead, an outdoorsman “stumbled upon” them while hiking through public lands. They then reported their unbelievable discovery to the Bureau of Land Management.

Working together with the Royal George Museum and the Denver of Museum of Nature and Science, the Colorado BLM organized an excavation team to carefully remove the fossils from their resting place. Experts believe the leg bones to be between 145 and 150 million years old.

The Royal George Regional History Museum already has exciting plans for the gargantuan bones. Using the fossils, the Colorado museum will give guests an up-close look at their preparation and preservation process.

The museum plans to present the fossils to the public on January 21. After that, experts and volunteers will spend several weeks preparing and preserving them at the museum. During that time, visitors to the museum can observe the workers in action prepping the fossils for display.

Colorado Paleontologist Explains Rarity of Recent Fossil Find

When Paleontologist Joshua Broussard arrived at the fossil site, he expected to find a 200-300 pound tibia. What he found, however, was beyond anything he could’ve imagined.

Laying right next to it, in exactly the right position, was the dinosaur’s fibula. For context, the tibia and fibula are the bones of the leg connecting the knee to the foot. Broussard then helped his colleagues to excavate and encase the fossils in plaster jackets for transport.

“Being a geologist, it’s also important to know where these came from as far as what exact layer it came out of, how old that rock is, what type of rock it is,” Broussard told Cañon City Daily Record.

“The specific layer that these were found in can tell you a lot about how it was deposited, where and why, just based on the rock that it’s encased in alone. That’s a really big clue for an expert like me. And that’s why it’s important that people leave them where they are.”

What makes the Colorado fossils even more interesting is that, unlike so many before them, they were perfectly intact. After millions of years beneath the earth, fossils tend to break. “The fact that they are intact and exactly how the leg was arranged when alive is really rare and important,” Broussard said.

Personnel from the Denver Museum of Nature and Science and BLM worked together to carefully excavate and encase the fragile fossils in plaster jackets. This kept them intact so they could be transported to the Royal Gorge Regional Museum & History Center, which is a federal repository, for proper preparation and stabilization work.

They are believed to be between 145 and 150 million years old.

“Being a geologist, it’s also important to know where these came from as far as what exact layer it came out of, how old that rock is, what type of rock it is,” Broussard said. “The specific layer that these were found in can tell you a lot about how it was deposited, where and why, just based on the rock that it’s encased in alone. That’s a really big clue for an expert like me, and that’s why it’s important that people leave them where they are.”