archaeology

Bones removed from a mastodon suggest that there were hominids in California 130,000 years ago

Issue # 255
may. 2017

Tom Deméré/San Diego Natural History Museum Marks and fractures in a fossilized bone of a mastodon suggest that it was removed deliberately by hominidsTom Deméré/San Diego Natural History Museum

Hominids were smashing bones of mastodons 130,000 years ago to extract marrow or make tools and other objects in the region that is now San Diego in Southern California, on the Mexican border. This highly controversial statement was based on findings of a study led by researchers from the Center for American Paleolithic Research in the United States (Nature, April 27, 2017). The group analyzed a set of bones from the extinct animal, found in 1992 during a highway construction project. Surprisingly, along with the material, there were stones typical of those prehistoric humans used to smash hard objects. The marks and characteristics of the fractures in the animal’s large bones, such as the femur, indicate that they were removed deliberately while they were still fresh, but the more delicate ribs and vertebrae remained intact. According to the researchers, the fact that the smaller bones were preserved and in good condition and that the material is concentrated in the same location rule out the possibility that the movement of water from an ancient river that flowed through there was responsible for this pattern in which the fossils were arranged. The only candidates for the act of smashing the larger bones would have been unidentified hominids, since there were no carnivores strong enough to break the huge femur of a pachyderm. Researchers conducted experiments in Tanzania using stones similar to those at the California archeological site to smash elephant bones and observed similar marks and fractures. The great surprise from the study was their finding that the mastodon’s skeleton was 100,000 years older than the oldest records of humans of the Homo sapiens species in the Americas. The age, which was difficult to establish, comes from analyses that measure relative levels of the elements uranium and thorium in bones. The finding caused a stir among archeologists and bioanthropologists because it suggested that the determination of when hominids arrived in America had to be completely reexamined. Many researchers will remain skeptical until more convincing remains from these ancient human beings are found.