To Spanish pre Historian Eudald Carbonell, the labor of a field archaeologist is planetary and, when one (archaeologist) works on the evolution of men, a country must not be considered as a boundary. What truly is fundamental is the knowledge and the thinking that regards human beings. Under this premise, he came to excavate a site in North America for the first time: Chazumba, Oaxaca, where investigators from the National Institute of Anthropology and History
(INAH) discovered a paleontological site with possible human presence.
The history of the investigation project of Oaxaca started in 2006 when a group of young settlers, who were exploring a ravine near their community, found bone fragments belonging to animals with big dimensions; the bones had fallen from an 11 meter [36.08 feet] wall. The group contacted the local authorities and they, in turn, contacted INAH. The paleontologist Joaquin Arroyo inspected the site and then verified that the bones had indeed belonged to extinct animals from the last stages of the Pleistocene. They inhabited the earth about 25,000 years ago.
In two excavation fronts located over the ravines walls, 40 meters [131.23 feet] square and 20 meters [65.61 feet] square respectively, investigators have found hundreds of gomphotheres (a type of pachyderm not unlike the mammoth but in smaller size), glyptodont, mylodon, giant sloth, deer, turtle, woodrat and rabbit, along with a bird species and an amphibian. Both sites have been explored during four cultivating seasons that took place in 2007, 2008, 2010 and the most recent was carried out this year (2013), which concluded last week.
In both places they have registered ten silex chips that seem to have been cut by rocks and not as the result of natural events. However, Ramon Viñas-Vallverdu and Joaquin Arroyo, co-directors of the Oaxaca project, have considered it necessary to find more of these objects in order to determine if they are the result of human work; in the same way, its necessary to apply to these objects lithic studies to determine if they have marks that might indicate usage.
Joaquin Arroyo pointed out that the silex chips are very similar to lithic materials found in other sites, such as El Cedral, located in San Luis Potosi. This site was excavated between 1977 and 1991, and whose studies point to the presence of men as far back as 31,000 years ago.
The specialists also said that two of the eremotherium (Eremotherium laullardi) bones found in Chazumba, have marks that seem to be cuts, this means that there is a possibility that the animals to which the bones correspond to were cut up by humans. Said hypothesis must be confirmed with further trace studies.
At present, the Oaxaca site is considered to be only paleontological, which alludes only to fauna (no human presence). The antiquity of the findings has been calculated to be around 25,000 and 20,000 years, given the animal species that were found in the area.
Archaeologist Iran Rivera Gonzalez, from the National School of Anthropology and History (ENAH), explained that the paleobotanic study has shown that during the Pleistocene, Chazuba had wooded vegetation with oaks and pine trees, very different from the actual vegetation. She also said that in the last analysis they found pollen from aquatic vegetation, which indicates there was a stable body of water nearby, possibly a lake.
The archaeologist has carried out the paleontological environment through palynology: We take a sample of distinct layers of earth every 5 centimeters [1.96 inches]. These are taken to the Palynology Lab and there we search for how many grains of pollen are recovered and to what vegetation families and genres they belong to, the results are very concrete but the analysis takes way too long, we must spend many hours watching a microscope.