Diatoms and chrysophyte cysts: Powerful tools for determining paleoenvironment and age of the Hueyatlaco Early Man site, Puebla, Mexico

No other archaeological site in the world is associated with such significant age and environmentally diagnostic diatom/chrysophyte cyst evidence as Hueyatlaco. Diatoms and cysts have been found in 147 samples (many collected by H. E. Malde) from 22 distinct stratigraphic units at or around the Hueyatlaco archaeological site. These samples have yielded 467 extant and 78 extinct diatom taxa and 44 extant and 39 extinct chrysophye taxa, many of which are age diagnostic indicators designating a minimum (Sangamonian sensu lato = 80,000 - ca. 220,000 yr BP) and a maximum (Illinoian = ca. 220,000 - 430,000 yr BP) age for the Hueyatlaco artifacts. Attempts have been made to discredit the Hueyatlaco artifacts and their in situ emplacement with such speculations as “redeposition” and “an inset unconformably into an older section”. The biostratigraphy and paleoecology of these numerous diatoms and cysts negate the likelihood of any redeposition, inset, or unconformity claims directly associated with artifact-bearing beds at Hueyatlaco. Those who insist on maintaining that humanity first arrived in North America during the Last Ice Age (Wisconsinian) or postglacial times are going to find it more and more difficult, if not impossible, to try to ignore and/or discredit the rapidly growing body of evidence supplied by diatom/cyst studies which indicate a pre-Wisconsinian (>80,000 yr BP) age for the Hueyatlaco artifacts.