It takes a lot to wow photographer Robert Clark.

Over his illustrious career, Clark has photographed more than 40 stories for National Geographic magazine, specializing in capturing the distant past of life and culture. He shot China’s exquisite feathered-dinosaur fossils. He watched researchers autopsy Ötzi the Iceman, the famous 5,000-year-old frozen mummy. And he took intimate portraits of people who lived and died 2,300 years ago—their leathery faces preserved in a bog.

But when he traveled to Alberta’s Royal Tyrrell Museum of Palaeontology last December and first laid eyes on his next photographic subject, he laughed.

Clark was staring at a 110 million-year-old fossil of a nodosaur, a type of plant-eating armored dinosaur. Its resting place undersea had helped fossilize the dinosaur’s armor, patches of its skin, some of its soft tissue—and what are likely remnants of the dinosaur’s last meal.

Discovered by an observant miner in 2011 and publicly unveiled on May 12, 2017, the fossil is the best-preserved nodosaur ever found, and arguably one of the most visually arresting fossils unearthed in decades. (Read the story of the fossil’s extraordinary journey.)

“It was like a Game of Thrones dragon,” Clark says. “It was so dimensional, like a prop from a movie.”

Shocked by the quality of its preservation, he endeavored to do the fossil justice for National Geographic’s June 2017 issue, taking pains to light the specimen in ways that highlighted its detailed features.

“This is pretty much the most impressive fossil I’ve ever seen, and I’ve seen a lot of great fossils,” says Clark. “This is kind of another level.”

Clark says that he felt a responsibility to document the fossil for perpetuity: He is likely to be one of the few photographers allowed to shoot it without the specimen under protective glass.

Beyond documenting the fossil’s scientific merit, he also recognizes how his photography can capture the public’s imagination, especially among children (some of whom, he adds, undoubtedly know more about dinosaurs than he does).