Megalodon (Otodus megalodon) are an extinct species of mackerel shark named for their enormous teeth. Megalodon are believed to be one of the largest predators that ever evolved, with a maximum length estimated to be anywhere from 47 to 67 feet and an average length of 34 feet. These estimates are mostly calculated from their well-preserved teeth rather than skeletal remains, which are largely incomplete. This is because megalodon, like all sharks, were cartilaginous fish (class Chondrichthyes) and had skeletons made out of cartilage instead of bone. Cartilage is a much less mineralized tissue than bone and doesn’t preserve well over time, as fossils or even on archaeological sites. Tooth enamel on the other hand is 95% mineral and lasts a very long time in the ground, between 3.6 and 23 million years in this case!
Sharks have many rows of teeth constantly forming and maturing in their jaws ready to quickly replace those that become worn or lost, and some species of sharks replace all of their teeth up to every two weeks. This rapid turnover is why shark teeth and fossils are so common in some locations. Incomplete fossils mean that there is still much to learn about megalodon. They were previously thought to be close relatives of the great white shark (Carcharodon carcharias) but have since been reclassified. There is still debate over what megalodon actually looked like, since their earlier divergence from great white sharks increases the variety of plausible body shapes beyond previous theories that megalodon looked like much larger, stockier great whites.
These megalodon fossils likely ended up in archaeological contexts here at Jamestown because colonists were just as interested in these unusual objects as we are today! Gentlemen at the time often kept a ‘cabinet of curiosities’ to display evidence of their travels, knowledge, and wealth but a fascination with unusual natural items would not necessarily have been limited to these gentlemen alone. Colonists may have picked up fossils eroding out of the banks of the James River as souvenirs of their adventures. Fossilized megalodon teeth, scallop shells (Chesapecten jeffersonius the state fossil of Virginia), and whale bones have all been found archaeologically at Jamestown and can easily be found on certain banks and beaches along the James today. However, in the early 17th century the colonists would not have known that these fossils were the mineralized remains of once living creatures. Natural philosophers like Nicholas Steno began to understand this connection later in the century, but many important breakthroughs in geology were not made until the 18th century.