75 million-year-old giant turtle's bone from fossil discoveries assembled

Paleontologists have assembled a giant turtle's bone from fossil discoveries made centuries apart.

"As soon as those two halves came together, like puzzle pieces, you knew it," Ted Daeschler, PhD, associate curator of vertebrate zoology and vice president for collections at the Academy of Natural Sciences of Drexel University said.

That surprising puzzle assembly occurred in the fall of 2012, when Jason Schein, assistant curator of natural history at the New Jersey State Museum, visited the Academy's research collections to better identify and describe a recently-unearthed fossil.

The discovery linked scientists from both museums to their predecessors from the 19th century, while setting the stage to advance science today.

The partial fossil bone that Schein had brought to the Academy was a recent discovery by amateur paleontologist Gregory Harpel.

Harpel thought the bone seemed strange and out of place when he noticed it on a grassy embankment, a bit upstream from his usual fossil-hunting haunt at a brook in Monmouth County, N.J. Visiting the brook to search for fossil shark teeth is a weekend hobby for Harpel, an analytical chemist from Oreland, Pa.

When he realized it was indeed a fossil, certainly much larger and possibly a lot more scientifically significant than shark teeth, he took it to the experts at the New Jersey State Museum, to which he ultimately donated his find.

Schein and David Parris, the museum's curator of natural history, immediately recognized the fossil as a humerus - the large upper arm bone - from a turtle, but its shaft was broken so that only the distal end, or end nearest to the elbow, remained.

Parris also thought the fossil looked extremely familiar. He joked with Schein that perhaps it was the missing half of a different large, partial turtle limb housed in the collections at the Academy of Natural Sciences of Drexel University.

That bone also had a broken shaft, but only its proximal end, nearest to the shoulder, remained. The coincidence was striking.

The scientists believe that the entire unbroken bone was originally embedded in sediment during the Cretaceous Period, 70 to 75 million years ago, when the turtle lived and died. Then those sediments eroded and the bone fractured millions of years later during the Pleistocene or Holocene, before the bone pieces became embedded in sediments and protected from further deterioration for perhaps a few thousand more years until their discovery.

They research is published in the Proceedings of the Academy of Natural Sciences of Philadelphia.