Fossilized Mammal Bone

Fossilized mammal bone has been found in multiple contexts at Jamestown including wells and cellars. But how does bone become fossilized, and why did the colonists keep fossils?

Fossils of materials like bone or plants are formed through various processes, including compression, molds and casts, (like the Stigmaria fossil), or most commonly through permineralization. In this process, the organic material of a previously living object is very slowly replaced over thousands or millions of years with minerals transported by moving water. This essentially turns the bone or plant into a rock! Bone, even of large animals, is usually porous and lightweight. However, when bone is fossilized, it becomes very heavy. The bones shown here and teeth from the giant Megalodon shark were both formed through permineralization.

The reason why fossils are recovered from archaeological contexts at Jamestown is unclear. One fossilized bone has markings along its edge suggesting it was used as a tool. Other fossils were likely kept as objects of curiosity by the colonists who may have come across them as they built the fort and dug into the ground to create their cellars and wells. The fossils shown here are likely whale bone based on their size and similarities to other whale fossils in the region. While the exact age of our fossilized bone is unknown, other whale fossils found in Virginia range from 3 million to 15 million years old! This places the bone in the geologic period of the Miocene, which had a great variety of land and sea mammals, some of which still exist today.

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