A considerable sensation was recently caused in the public mind, both in America and Europe, by the announcement of the discovery of a fossil human bone, so associated with the remains of extinct quadrupeds, in “the Mammoth ravine,” as to prove that man must have co-existed with the megalonyx and its contemporaries.
- Sir Charles Lyell, 1849
While Dickeson was in Natchez, Mississippi, he took a break from excavating Native American mounds to try his hand at paleontology. He was digging in Mammoth Ravine, a site rich with fossils, when he discovered a fossilized human pelvis. What made this find distinctive was that the pelvis (which came to be known as the Natchez Pelvis) was located in a layer of clay below the fossilized remains of several extinct megafauna. Dickeson argued that this order of stratigraphy meant that humans had lived before or at the same time as these extinct animals.