A few days ago, the PCP-PIRE team in Panamá headed to the studios of Panama’s national public radio station for an interview with Louissis, a woman who has been the host of a popular radio show for twelve years running (Momentos con Luissis). We positioned ourselves in front of the microphones and began to talk about the work we do in the canal, our experiences living in Panama, and the upcoming talk that Jorge is giving at the Smithsonian’s facilities in Punta Galeta, near the Caribbean port of Colón. Continue reading
And we’re back! A ton has happened since our last post. A huge group of our scientific partners at the University of Florida spent a week helping us collect fossils in Panamá. It was a wild time, with many folks downing Gatorades to stay hydrated in the blazing afternoon sun. Our combined efforts led to many fossil finds!
Anyhow, we are picking up where we left off. Last time, I described the heavy lifting we did to clean off one of our fossil localities and increase productivity. After we moved all of that sediment, Jeremy found the distal end of a humerus, possible from a fossil rhinoceros! We’ve continued down this path, moving to a new exposure of the Cucaracha Formation.
We just finished up a two-day project to revive our Centenario 6 locality – a fossil collection site where previous researchers have found unique fossils crucial to our understanding of American biogeography. The effort was literally massive. We must have busted up and shoveled nearly one thousand pounds of rocks and sediments with our rock hammers and pickaxes.
In order to continue finding fossils, you have to work to expose layers where bones are most-concentrated – a result of the environmental conditions where the sediment was being laid down millions of years ago. This unit (Cucaracha, ~19 Ma) has produced incredible finds, including part of a jaw from a “bear-dog“ This a carnivorous mammal that originated in the “Old World”, and an Antracothere, which is an artiodactyl ungulate closely related to hippos and which is a sister taxa of whales. These fossils are critical clues, not only because fossil carnivores from this period are incredibly rare, but also because both of these fossils strongly link the mammals living in Panamá during the Miocene to those living contemporaneously in North America. The more evidence we find, the better our picture of Panamá and its role in the relationship between North and South America before the closure of the isthmus. Also, we’re looking to find some monkeys to better complete the picture.
Stay tuned for more! And Go Gators!
This has been an incredibly exciting week for us out here in the field. Yesterday, we went to the Las Cascadas formation to collect sediment for washing and sieving. The quarry had been disappointing us recently, so we were just making a quick stop before we headed on to another locality. As we were showing a guest around the site, I had some free time and I began to poke around in the sediment. Almost immediately, I found a canine. Then another. I called over our supervisor Jorge Moreno so that he could take a look. Over the next few hours, the five of us uncovered more and more – a tooth here, some bone there – and by the time we were done, we had extracted what we believe to be the jaw of a camel! I’m waiting for some photos and conducting some additional research, but I promise I will post more about this soon!
Today, our good luck followed us to the Centenario locality. Shortly after Jeremy and Sophie set about extracting the turtle carapaces they has discovered earlier this week, Jeremy uncovered a big chunk of shining black bone. We began our speculation… It seemed lodged in, like it continued for a bit into the matrix. Were we seeing an epiphysis (end) of a long bone? Could it be a crocodile quadrate (said Jorge)? We had to see more.
This conglomeratic layer had been good to us recently, so we decided to give it a good cleaning. With our machetes, shovels, hammers, and pickaxes, we chopped through and uprooted elephant grass before digging out sediment and exposing a horizontal bench above our find. “Opening the quarry” allows us to work from the top down, increasing access to this productive layer and making it easier to remove sediment without damaging our fossils. Check out the before and after pictures of our quarry below! Tomorrow, we’ll go back to Centenario and continue excavating the cluster of bone that we uncovered today. More updates to come!
¡Hola! It’s Adam, and I’m excited to share a bit of what I’ve learned with my first post.
It’s been nearly a month since I stepped into the swampy air of the Panama night. Since then, I’ve gotten used to the heat, but I also realized that the humidity now is nothing compared to what will come. We’re now between the dry and the wet seasons, and each day in the field brings a hotter sun than the last.
These are the good days, as far as hunting fossils is concerned. Dry weather keeps the rock brittle and easy to pick, but as soon as moisture creeps into the sediment, you end up trying to squeeze bones out of a goopy mess. Especially when the matrix (the rock that encases the fossils) is full of clay.
Today, I thought I’d write a bit about what we’ve been up to. I’ve tried to spell things out, in case some of this blog’s followers aren’t well versed in geology or evolutionary biology.
The rocks we work are all between 21 and 19 million years old, from a geologic period called the Miocene, however, these rocks represent a diversity of species and environments that existed in Panama at that time.
But fossils can be tricky – like when you find whole tree trunks a few meters away from tiny crab fossils! Are you on land or at sea?
We encountered this situation at a locality of the Culebra Formation just the other day. So, how do you solve this puzzle?
Based on the many characteristics of the rock unit, we can gain an understanding of what environment we’re seeing when we search through these rocks. The field of sedimentology asks questions like, “What minerals are present? Is it made of cobbles, sand, or mud? Are these pieces jagged or smooth? How is the sediment layered?” These observations narrow down the possible scenarios that led to what we see today.
In the area we visited, research has shown that these rocks formed off the coast, close enough for plants to wash in from the land. They were probably carried by rivers that emptied into shallow seas.
Understanding this area’s geology and stratigraphy (the patterns of layering, both at small and large scales) is crucial to interpreting Panama’s past and the biological diversity of the Americas as a whole. The isthmus is the only land connection between these two continents, and scientists have shown that this region has played a very important role in the broader development of ecosystems in both North and South America.
It’s exciting to be part of such a fascinating project! Hope you enjoyed this info. Stay tuned for more!
P.S. If you want to get to know the new field interns, check out the most recent PCP-PIRE eNewsletter.