About 160 years ago, a fossil was found in New Jersey that scientists were able to use to describe the sea turtle Atlantochelys mortoni. And this week, another fossil was found in a nearby area that scientists believe to be part of the same creature. The fossil fragments are a perfect match and now give scientists more information about one of the largest sea turtles that ever lived.

The original fossil was found in 1849 and was identified to be part of the sea turtle's broken arm bone. Since then it's been sitting in the Academy of Natural Sciences of Drexel University — until recently, when amateur fossil paleontologist Gregory Harpel presented a fossil he discovered on an embankment in Monmouth County. According to BBC News, Harpel thought it was a rock at first, but then noticed marks he believed to be shark bites and knew he had stumbled upon something more significant. The fossil was then donated to the museum at Drexel, where Vice President of Collections Ted Daeschler, PhD, and other experts immediately identified it as humerus, or the large upper part of the arm — the exact part the original fossil was missing.

"I didn't think there was any chance in the world they would actually fit."

They placed the two fossils side by side and discovered they fit perfectly, proving the fossils were two halves of the same bone from the same sea turtle. Not only does this discovery give researchers more information about A. mortini — including that it's one of the largest sea turtles that ever lived, measuring ten feet from tip to tail — but it also questions the theory that fossils will break down when left exposed for more than a few decades. If this fossil was able to survive for over a century while exposed, that means it's possible that other fossils could do the same.