This week’s Fossil Friday (the 13th) post features an anthracothere astragalus! This specimen was found in El Lirio Norte of the Las Cascadas Formation and is early Miocene in age. The astragalus is a tarsal, which is a bone found in the ankle. Astragali are very helpful in determining what kind of animal the bone might have belonged to. For example, the “double-pulley” morphology of this anthracothere astragalus is indicative of artiodactyls, so you would also be able to see this kind of morphology in the astragali of camels, deer, and other artiodactyls.
Diagram of how CT scanning works. (courtesy of Imaginis.com)
I think many people these days are familiar with CT scanning, or its cousin, the MRI, even more so. But many probably don’t know how it works. Using x-rays shot thru an object in successive slices, a layer by layer analysis of a structure can be performed. When stacked together, these images can digitally reconstruct an object and its insides.
As the other interns have previously stated, our trip to Panama over Spring Break was a huge success! Here’s my take on it:
Panama City was an amazing place to visit and I thoroughly enjoyed exploring the city. My favorite part however was the time spent in the field. I mostly spent my time at Las Cascadas. Many cool fossils were found (protoceratid skull, snake vertebrae, horse teeth, and many more) and although it was hot we had a great time. I thoroughly enjoyed myself. I also was able to explore a few marine sites and find various crab and shrimp fossils which was really fun and different for me. Below are some pictures from the trip.
My name is Will Tifft and I am one of the PIRE interns working in invertebrate paleontology. I graduated from Hamilton College this past May with a Bachelor’s Degree in Geoscience. Before coming to the Florida Museum of Natural History I spent the summer interning at the Paleontological Research Institute (PRI) assisting a PhD student with his work on Eocene posters from the Atlantic Coast. In the future I’m interested in studying brachiopods as well as microfossils. While working on the PIRE project I am mainly interested in getting the most research experience I can.
Small projects using several prepping techniques.
For the past month I have been working on preparing many of the invertebrate fossils brought back from Panama. This process includes doing simple things like gluing specimens back together and hardening them all the way to using the rock saws and air abrasive unit. Besides gluing, the first prepping project I worked on used the air scribe, which is a small jackhammer that uses compressed air to remove matrix from around a specimen. This has become the main process by which I prepare specimens. The air abrasive unit uses compressed air to shoot sodium bicarbonate pellets at the specimen to remove smaller amounts of soft matrix. When used correctly it is much less damaging to the specimen than the air scribe.
Shell being glued with Elmer’s glue and supported by sand.
While I was working on projects with the air scribe and abrasive unit, I was also working on several shells and other specimens that had to be glued back together. For most of these Elmer’s glue is sufficient enough to hold them together. In order to hold the specimen in the correct position while it is drying, a sandbox is used. The sand gives more support to the pieces while they dry than placing it on the table or even trying to hold it in place. It also allows the person preparing it to work on other projects while it dries. When this isn’t strong enough, Butvar or Epoxy is used, though it is more damaging to the specimen if it gets on the shell or exposed surface. Often times specimen that are still contained with a partial matrix are brittle and will fall apart when exposed. In order to prevent the specimen from falling apart B-72 is applied to the surface. This soaks into the shell and gives it some extra strength.
Jorge Moreno Bernal and Fall 2014 Field Intern Lillian Pearson collecting a partial fossil peccary jaw covered in plaster. Photo courtesy of Hannah O’Neill.
Application Deadline: 5PM EST on March 9, 2015
Are you interested in a geology and paleontology? How about traveling to Central America and brushing up on your Spanish? Want to gain valuable field experience excavating fossils while enormous cargo ships pass by in the distance?
If so, then we have the perfect internship opportunity for you.
PCP-PIRE is currently accepting applications for its Summer 2015 cohort of field interns. The goal of the PCP-PIRE field internship program is to expose students to geoscience field and research techniques in an international setting as we make new fossil discoveries and refine the stratigraphy of the Panama Canal Basin. Interns are also encouraged to explore the culture and natural history of Panama and expand their outreach abilities in conveying the importance of geology and paleontology to the public.
We would like to welcome the Fall 2014 cohort of PCP-PIRE field interns back to the Florida Museum of Natural History. After over three months of fieldwork, Hannah, Daniel, Adam, and Lillian returned from Panama this week and will be working at FLMNH until December 19th. They will be processing fossils from Panama and doing fossil preparation. The interns have started off by helping prepare a lumbar vertebra of a fossil rhinoceros from the Cucaracha Formation. The vertebra has been broken into several pieces and the interns are cleaning the pieces so that they can be put back together later. It’s quite a change from working out in the field in Panama, but we are happy to have them back and to have their help here at the museum!
Preparing a fossil requires a variety of tools, some of which are shown here. Top left to bottom right: spray water bottle, lubricating oil for airscribes, acetone, PVA, carbide picks, brushes, a PaleoAro and a microjack (airscribes of different sizes and strengths), dust mask, goggles, and ear muffs for noise protection.
The first project I got started on at FLMNH was preparing a fossil dugong from the Culebra formation of the Panama Canal. My main focus has been on a cluster of vertebrae that are held together by a carbonate and siltstone matrix. The process of preparing this fossil is rather slow going because the matrix is extremely hard and nearly the same color as the bone. To help distinguish them, the fossil is sprayed or brushed with water to remove dust and help bring out the color of the bone. While it is damp, I use carbide picks and airscribes (basically handheld jackhammers) to remove the matrix. The goal at this step of preparation is to remove as much matrix as possible while leaving a thin layer just above the bone and to leave any areas where it is too difficult to distinguish between bone and matrix. Next, a thin layer of PVA, a glue reversible with acetone, is added to protect the bone when it is placed in a diluted formic acid bath. The acid breaks down some matrix but does not damage the bone, although some etching can occur over time. The fossil is then soaked in running water to remove any remaining acid and the PVA is removed to begin the process of manually removing matrix over again. Broken pieces of bone often become loose after the bath and must be secured with glue before continuing.
The fossil lab station where Dawn prepares the dugong vertebrae. She uses a surgical microscope that can easily pivot to get multiple views of the fossil while she uses tools to remove matrix.
Preparing this fossil has taken a lot of time and the effort of many people, and it still requires much more before it is finished. But progress is being made; when I started I couldn’t see through the neural canal of one vertebra, but now I can! Once preparation is completed, this fossil promises to provide us with interesting new information on Miocene dugongs from the Panama Canal area.
Sean Moran recently traveled to Santa Cruz, CA to work with high school teachers developing lesson plans incorporating paleontology. Read his post on GABI-RET’s blog!
Sean Moran shows off a geological sample taken at Capitola Beach. Photo by Rob Hoffman.
The 3-5 Ma (Pliocene) Purisima Formation, a marine sedimentary unit that is fossiliferous and interpreted to preserve marine shelf deposits, crops out at Capitola Beach as well as several other locations around Santa Cruz. The fact that it is close to many local schools and provides material for several type of geology lessons makes in an appealing place for class field trips. The hope is that these trips with teachers will catalyze the creation of lesson plans centered on Capitola Beach [read more on GABI-RET].
Wes von Dassow (back, left) spoke with students in the Santa Cruz schools during the last week of October. Photo by Laura Beach.
It’s already Thursday and I am just sitting down to write about the conversations I’ve been having with teachers and classrooms full of students since Monday. It’s been really interesting talking to and, most times, having back and forth conversations with these classes. I’ve been told how some classes can be more attentive or rambunctious based on class “personality”, the time of day, or the general malaise that seems to cloud kids natural curiosity throughout high school. But, who am I to complain about those few classes? I remember being the same way to some degree at their age, which was only 4 years ago for me! [read more on GABI RET]
Cristina Robins with her poster (co-authored with Claudia Grant, Aaron Wood, Shari Ellis, and Bruce MacFadden) about the various outreach methods used to communicate the PCP PIRE scientific findings in the digital age.
Austin Hendy showcases the FOSSIL project poster right across the aisle from the PCP PIRE poster.