Editor’s Note: Josh Robinson is a postdoctoral researcher working with IHO on the John Templeton Foundation grant projects. We are excited to hear about his research in Argentina!
When we think of field or museum work, most paleoanthropologists immediately imagine a trip to Africa or perhaps Southeast Asia. Argentina, in contrast, is probably one of the last places one would guess. So why is a paleoenvironmental scientist who has done all of his research up to this point in Africa going to South America?
Well, South America is home to a thriving community of New World monkeys (or platyrrhines) with a long evolutionary history on the continent of about 25 million years. During this time, New World monkeys were isolated from Old World monkeys (found in Africa and Asia). The highly successful and diverse evolutionary radiation of New World monkeys offers a model for studying parallel evolution in anatomy and behavior with Old World monkeys in Africa. More data on the environmental and ecological contexts of the evolutionary history of New World monkeys allows for a fine-tuning of these comparative evolutionary models. This is where I come in.
While gathering my dissertation data, I had the great pleasure to work with Dr. John Fleagle of Stony Brook University on the environments in the Kibish Formation of Ethiopia. After completing a paper on the Kibish Formation earlier this year, Dr. Fleagle asked if I would be interested in doing similar work in Argentina. As you may imagine, the evolutionary history of New World monkeys was nowhere near being on my radar, but I figured I’d hear him out. I mean, I’ve always heard Argentina has great steak and wine, and what’s a better way to escape the summer heat in Arizona than to head down to a southern hemisphere winter. Dr. Fleagle has been working the Pinturas and Santa Cruz geological formations in Argentina’s Patagonia region for nearly three decades. These formations date to the Early and Middle Miocene (17 to 10 million years old) and have produced a record of a diverse mammalian community. One of the big differences between these two regions is in the number of fossil New World monkey species found in each. The Santa Cruz Formation, which is closer to the coast, has only yielded one fossil monkey species, but five or six fossil monkey species have been found in the Pinturas Formation.
My job will be to work with the fossil teeth of all of the mammals collected by Dr. Fleagle and his team over the years to sample some of the tooth enamel for isotope analysis. What is isotope analysis? When animals eat and drink, the carbon and oxygen isotope signatures get incorporated into their developing tooth enamel. This signal is preserved because tooth enamel does not fossilize like bone. We are able to analyze these values to determine what type of food the animal was feeding on and whether it was a wet or dry environment. If we were to sample your teeth I bet we would get a very strong signal indicating heavy corn consumption! Dr. Fleagle thinks the Pinturas Formation may have been a much wetter environment than the Santa Cruz Formation because of the larger number of fossil monkey species.
I will be traveling to Argentina on June 23 for three weeks. Most of the time I will be in the capital, Buenos Aires, working at the Museo Argentino de Ciencias Naturales. Some of the collection, however, is stored at a regional museum in Puerto Madryn, so I will be taking an overnight bus ride there during my trip. We hope that the data we get from this pilot project will help us understand better the diversity of the environments of the early evolutionary history of New World monkeys. It may also provide some insight to differences between South America and Africa/Asia, which could be critical to understanding the different evolutionary trajectories of monkeys on those continents.
I look forward to the adventure to this place to which many of my colleagues and I have not ventured and to sharing my new experiences with you along the way!