Uncovering Human-Megafauna Interactions in the Drowned Caves of the Yucatan Peninsula Mexico
North America has long been a focal point in discussions of the timing and cause(s) of Late Pleistocene megafaunal extinctions, playing a prominent role in debates relating to the relative impacts of human arrival and climate change on the demise of large mammals during this period. In Mexico, on the Yucatan Peninsula, a series of submerged caves and sinkholes (cenotes) have not only provided evidence for human presence 13,000 - 12,000 years ago, but have also preserved extensive records of vertebrate fauna, including both extant and extinct megafauna. During the Last Glacial Maximum, the peninsula was higher and the sea level more than 100 m lower than today, meaning that the cave systems in the peninsula were dry and accessible right up until the middle Holocene, serving as natural traps for humans and animals. From 8,000 years ago, warmer and wetter conditions, alongside a rise in sea level, resulted in cave submergence and an expansion of the present-day tropical and sub-tropical vegetation of the region (Figure 1).
Since the 1980s, cave divers have explored the submerged Sac Actun cave system, which is currently the longest known in the world, but it was not until the first decade of the 21st century that underwater archaeologist from the Instituto Nacional de Antropología e Historia in collaboration with other research centres starts the documentation and recovery of paleontological and archaeological evidence from about a dozen sites in the peninsula. Given its record of human presence throughout the Late Pleistocene period, the sites of this region present the possibility to explore the varying impacts of climatic change and human presence on different megafaunal populations.
This project aims to apply novel methodologies such as Zooarchaeology by Mass Spectrometry (ZooMS), stable isotope analyses, radiocarbon dating, and taphonomy (including cutmark analysis, site formation studies) to megafaunal remains from the caves in the Cenote Iza, Cenote Papakal, Cenote Ziizha, Cenote Izah, Cenote San Antonio, Taj Mahal Cave, Cenote Sipa and, Cenote Las Palmas, which have not been previously applied on faunal materials from these contexts. Such work has the potential to not only massively contribute to understandings of processes of megafaunal extinction in North America, but also to assess the interactions between our species and megafauna in this region and to build up more detailed records of megafaunal chronology and ecology in a little-studied portion of the Americas (Figure 2).
Arroyo-Cabrales, J., Polaco, O., Johnson, E., and Ferrusquía-Villafranca, I., 2010, A perspective on mammal biodiversity and zoogeography in the Late Pleistocene of México. Quaternary International. 212. 187-197. 10.1016/j.quaint.2009.05.012.
Ceballos, G., Arroyo-Cabrales, J., and Ponce, E., 2010, Effects of Pleistocene environmental changes on the distribution and community structure of the mammalian fauna of Mexico. Quaternary Research, 73, 464–473.
Chatters, J., Kennett, D., Asmerom Y., Kemp B., Polyak V., Nava A., Beddows P., Reinhardt E., Arroyo-Cabrales J., Bolnick D., Malhi R., Culleton B, Luna Erreguerena P., Rissolo R., Morell-Hart S., Stafford T., 2014, Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans, Science, Vol. 344, Issue 6185, pp. 750-754.
González, A.G., Sandoval, C.R., Mata, A., Sanvicente, M.B., & Acevez, E., 2008, The Arrival of Humans on the Yucatan Peninsula: Evidence from Submerged Caves in the State of Quintana Roo, Mexico, Current Research in the Pleistocene, 25:1–24.
Ferrusquía-Villafranca, I., Arroyo-Cabrales, J., Martinez-Hernandez, E., Gama-Castro, J., Ruiz-González, J., Polaco, O., and Johnson, E., 2010, Pleistocene mammals of Mexico: A critical review of regional chronofaunas, climate change response and biogeographic provinciality. Quaternary International - QUATERN INT. 217. 53-104. 10.1016/j.quaint.2009.11.036.
Haynes, G., 2009, American Megafaunal Extinctions at the End of the Pleistocene, Springer Nature, 210 pp.
Koch P.L. and Barnosky A., 2006, Late Quaternary Extinctions: State of the Debate, Annu. Rev. Ecol. Evol. Syst.. 37:215–50
Metcalfe, S.E., O’Hara, S.L., Caballero, M.,Davies, S.J., 2000, Records of late Pleistocene-Holocene climatic change in Mexico-A review: Quaternary Science Reviews, 19, 699–721.