A new study from the University of Florida determining the age of skeletal remains shows that humans reached the western hemisphere during the last ice age Y they lived together with extinct giant mammals.
The study, published May 3 in the Journal of Vertebrate Paleontology, addresses the century-long debate among scientists about if human and mammal remains found in Vero Beach in the early 1900s they date from the same period. Using rare earth element analysis to measure the concentration of absorbed metals during fossilization, the researchers show that modern humans in North America coexisted with large extinct mammals about 13,000 years ago, including mammoths, mastodons, and giant ground sloths.
- MacFadden along with Purdy
“The Vero site is still the only place where there is an abundance of human bones, not just artifacts, associated with animals.", Says the co-author Barbara purdy, Emeritus Professor of Anthropology and Emeritus Curator of Archeology at the Florida Museum of Natural History on the UF campus. "Scientists who disputed the age of human remains in the early 20th century did not want to believe that people had reached the Western Hemisphere so soon. And 100 years later, every book written about North American prehistory includes the site and the existing controversy.”.
Following the discovery of fossils in South Florida between 1913 and 1916, some prominent scientists convinced researchers that human skeletons were of more recent burials and not as ancient as animals, a question that was left unanswered because there were no methods to date them.
“The incorporation of rare earth elements is time dependent, so an ancient fossil will have many different concentrations of earth elements on the bones than a recent human burial.”Says the main author Bruce macfadden, Curator of Vertebrate Paleontology at the Florida Museum. "We found that human remains had statistically the same concentration of these earth elements as fossils”.
The little information known about first humans to appear in North America it is based on bone fragments and artifacts, as well as stone tips used for hunting. Other sites in California, Montana, and Texas show human presence around the same period based on artifacts, but two complete human skeletons were found at the site of Vero Beach.
When bones begin to fossilize, they absorb elements from the sediment around them, and tests are effective in distinguishing between different ages of fossils deposited in the same location. Instead of radiocarbon dating, which requires the presence of collagen in the bones, the researchers use mass spectrometry to compare the earth elements in the Vero Beach specimens because the lack of collagen makes radiocarbon dating impossiblesays Purdy.
The researchers analyzed samples of 24 human bones and 48 animal fossils in the Florida Museum collection and determined that the specimens were from the time of late Pleistocene, about 13,000 years ago. Although analyzes performed using this method are not as accurate as those for radiocarbon, Purdy says that the significance of the human skeletons found at Vero Beach is unquestionable in terms of its presence in the western hemisphere.
- Purdy next to the skeleton of a mammoth
“It is important to note that the authors did not provide an absolute or chronometric date, whereas the geochemistry shows that the geochemical elemental traces are the same, so the bones must be the same age.", He says Kenneth Tankersley, an adjunct professor in the department of anthropology and geology at the University of Cincinnati.
The native fauna during the last Ice Age it ranges from extinct jaguars and saber-toothed tigers to shrews, mice, and squirrels that are still present in Florida. Researchers speculate that humans could have been more nomadic than animals because there was less water than in later years, Purdy says.
“Humans could have followed animals for food supply, but that's all we know”, says purdy. “We know what some of their tools are like and we know that they were hunting extinct animals, but we do not know anything about their family life, nor do we know how they raised their children and what they did after death.”.
The study includes as co-authors Krista Church, from UF and the University of Texas, and Thomas Stafford Jr., from Stafford Research in Colorado and the University of Copenhagen.
“Vero is a historical context for the development of archeology, it is the origins of the people of America”Says MacFadden. "The place is known in the literature, but it has been discounted, so we are reviving a kind of understanding about the importance of the locality and using new techniques to revive the question about the antiquity of humans.”.
Source: University of Florida
Graduated in Journalism and Audiovisual Communication, since I was little I have been attracted to the world of information and audiovisual production. Passion for informing and being informed of what is happening in every corner of the planet. Likewise, I am pleased to be part of the creation of an audiovisual product that will later entertain or inform people. My interests include cinema, photography, the environment and, above all, history. I consider it essential to know the origin of things to know where we come from and where we are going. Special interest in curiosities, mysteries and anecdotal events in our history.