Fossil Friday 3/27/15: A protoceratid

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UF 237877, the right maxilla of Paratoceras wardi. (Photo © VP FLMNH)

On this Fossil Friday I would like to present a protoceratid, Paratoceras wardi. The specimen shown here is a right maxilla with the second through fourth premolars (P2-P4) and three molars (M1-M3). It was found at the Centenario Bridge (Cucaracha Formation) and is early Miocene in age.

Protoceratids are extinct artiodactyls that are closely related to camels but whose later forms resembled deer in that they had horns. Although protoceratid fossils are fairly common in Panama, especially in localities such as the Gaillard Cut (Cucaracha Formation), specimens with cranial morphology, an important taxonomic identifier, have not yet been found in Panama.

References:

MacFadden, B. J. North American Miocene Land Mammals from Panama. (2006). Journal of Vertebrate Paleontology 26(3): 720-734.

Prothero, D. R. (1998). Protoceratidae. In C. M. Janis, K. M. Scott, L. L. Jacobs (Eds.), Evolution of Tertiary Mammals of North America (pp. 431-8). Cambridge, England: Cambridge University Press.

Digital Paleontology

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.

I’ve had some experience while working at the American Museum of Natural History in preparing fossils for CT scanning, and even seen the machine in action, but I’ve never actually operated a scanner or performed a scan. Next week that changes. I get to help scan a whole series of tiny mammal teeth. While the scanning itself will be handled by the scanner, the brunt of the actual work will be setting up the specimens for the scan. No easy task when there are dozens of teeth each millimeters long. Scans can take several hours so, for the sake of time, small fossils are normally mounted together and scanned in groups. Huge priorities are making sure that the teeth don’t move during the scan, they aren’t touching (making it more work to digitally process after) and that they are recoverable afterward, so thoughtful consideration must be given to the way they are mounted. We don’t want to jumble small specimens and have to spend valuable hours doing the near impossible, completely avoidable, task of teasing apart jumbled specimens.
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Intern Justy Alicea working on surface scanning a fossil turtle skull.

While we do that, I am also working on finishing up my first surface scan. Earlier in the week I finished training using the NextGen surface scanner by scanning the turtle skull Im working on. A surface scanner is different than a CT scanner in that the surface scanner only captures surface data. It cannot see through a specimen. Simply put, you are making a digital shell or cast of an object. The scanner contains both lasers and cameras. As the scanner takes a picture, it uses its lasers to scan the surface of the object and gauge distance, giving it the ability to create a 3 dimensional model. It repeats the process at different angles giving you a highly accurate representation of the object. The scan itself is pretty easy to set up and although the process for stitching and trimming the individual scans isn’t difficult, it is time consuming.

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Work in progress surface scan of fossil turtle.

It’s exciting to add these powerful methods to my toolkit and be able to produce these impressive scientific images. Knowing how to do this now will give me a significant head start over my future classmates when entering graduate school .

PCP-PIRE on the MioScene – PCP-PIRE y la radio

Last week, our supervisor Jorge Moreno Bernal posted on the blog that we made the front page of La Prensa, one of the top-two national newspapers. Well, this week, we’re on the radio!

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Left to Right: Sophie Westacott, Jorge Moreno Bernal, Louissis. In the studio!

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.

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Information about the talk in Colón. Información sobre la charla en Colón.

The interview was a huge success! Though, we must admit, Jorge did most of the talking. We were a bit intimidated by the microphones in our faces in combination with our less-than-perfect Spanish. The program aired this morning at 9 AM, and it was great to hear our voices being broadcast throughout the country as we explained to citizens how important Panama is for our understanding of climate and biology throughout the entire world. If you would like to listen to the program and you live in Panama, you can hear the whole show at  Nacional FM: 101.9 Panamá, Colón, and Darién; 100.3 in the central provinces; 92.5 in Chiriquí and Bocas del Toro. Go Gators!


La semana pasada, nuestro jefe Jorge Moreno Bernal escribió en el blog sobre un artículo que salió en el periódico nacional La Prensa, sobre el trabajo que estamos haciendo en el Canal. Y ahora, ésta semana ¡estamos en la radio!

El lunes, el equipo PCP-PIRE en Panamá fue a los estudios de la estación de radio pública nacional para una entrevista con Louissis, una locutora que dirige el programa Momentos con Louissis. Nos sentamos delante de los micrófonos y hablamos de nuestro trabajo buscando fósiles en el Canal, de nuestra experiencia viviendo la cultura panameña, y sobre una charla dará Jorge mañana en Colón, organizada por el Smithsonian.

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Jorge Moreno Bernal (PCP-PIRE) y Luissis en el estudio.

¡La entrevista fue un gran éxito! Fuimos intimidados por los micrófonos en nuestras caras y por nuestro no tan perfecto español, por lo que Jorge fue el que más habló. Sin embargo, disfrutamos escuchar nuestras voces en la radio y así mismo, los disfrutamos poder transmitir a la gente en Panamá la importancia de comprender el clima, la biología y la geología no solo de Panamá sino de todo el mundo.

Si quieres escuchar el programa, salirá éste domingo a las nueve por Nacional FM: 101.9 Panamá, Colón, y Darién; 100.3 Provincias Centrales; 92.5 Chiriquí y Bocas del Toro.

¡Vamos Alligatores!

Faults of the Empire

Sonia sketching the outcrop

Sonia sketching the outcrop

In a previous post Sonia explained the paleohistory  of the isthmus, from its volcanic  beginnings to recent sedimentation. This history has been pieced together by geologists interpreting the rocks wherever they poke out of the thick tropical vegetation.  We look at how the rock layers are stacked, at the size of the crystals or sediment grains that compose them, at the color the rock turns where it is exposed to air and water. A limestone suggests a shallow marine setting, while a basalt is evidence of volcanism.

Calcareous sandstone/siltstone fold

Calcareous sandstone/siltstone fold

Geologic history is important to the paleontologist too because fossils are nearly useless to science unless their place in time and space is understood. For this reason we headed back to Empire locality Thursday, March 12, and again this Thursday, not to search for any fossils but to try to interpret the rocks encasing them. Our colleagues who visited a couple weeks ago collected many plant and invertebrate samples from these layers, so any new information about the rock ages or depositional settings will be useful.

Breccia with vesicular basalt clast

Breccia with vesicular basalt clast

The outcrop is a stratigraphic mess. Faults are so pervasive that it feels like we’re standing on the shards of a shattered mirror. A folded weathered siltstone swirls delicately, bewildering our sense of verticality. Gray conglomerate lenses appear for a meter or two then pinch out again, while a pretty pink quartz arenite fault block ends as abruptly as it starts. Where to begin?

Last week we clambored all over the exposed rock, exploring. Today we picked a spot and made a rough stratigraphic column, describing the sequence from bottom to top.

Sonia, Adam and Jeremy measuring the section with a  Jacob's staff

Sonia, Adam and Jeremy measuring the section with a Jacob’s staff

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Examining the rocks. Photo courtesy of JW Moreno-Bernal

We measured the dip–the angle at which these sedimentary layers are tilted–then used a Jacob’s staff to determine the actual thickness of the beds as we walked in a straight line up the section. I had never used a Jacob’s staff before but the others gave a great lesson and it turned out to be a lot of fun! We described the rock as best we could, arguing over the coarseness of a sandstone or whether the bedding could be called ‘lenticular’, and came up with some hypotheses. There are some tuff (volcanic ash) units, which we think might correspond with the upper Las Cascadas Formation, topographically above some calcareous sandstone containing oysters and other shells that reminds us strongly of other Culebra Formation outcrops. Because Las Cascadas is stratigraphically below Culebra, this would mean that the section is overturned, at least along the line we were walking. We remain puzzled by a hard, blue rock that cuts across the tuff, and we’re working on getting ahold of a higher resolution GPS so we can start to map the area. We’ll definitely be going back to try to pull a straight story from a very tangled rock. More soon! Go Gators! DSC_0110

Una breve historia geológica de Panamá

(in English)

IMG_0588Según nos hemos enterado, el grupo de visitantes de la Universidad de Florida acaba de regresar de su visita en Panamá; durante el cual pasamos mucho tiempo buscando fósiles en el canal. ¡Los pasantes del museo probaron por primera vez el sol de Panamá!  El viaje salió muy bien, y muchos fósiles fueron descubiertos.

Además de cazar fósiles, también pudimos visitar el BioMuseo. Estando allí aprendimos un poco acerca de la historia geológica de Panamá. Disfruté escuchar mas sobre el contexto de esta área de campo tan importante. Después de todo, estos fósiles que buscamos tan desesperadamente son parte de una historia mucha mas grande, la cual me gustaría discutir brevemente hoy: la historia geológica de Panamá y las implicaciones del cierre del istmo centroamericano.

El exhibición del BioMuseo empezó con el origen mismo, un muy buen lugar para comenzar.

Antes de que Panamá fuera una masa sólida de tierra, el área estaba formada por un arco volcánico, formado por volcanes submarinos causados por la subducción tectónica. Los “colchones” de basaltos, las rocas mas viejas de Panamá, marcan el comienzo de este punto de la historia geológica. Una serie de rocas volcánicas y plutónicas se formaron durante todo este proceso. Estos volcanes submarinos eventualmente crecieron a medida que se levantaban hasta convertirse en pequeñas islas emergidas. Esto comenzó el proceso de sedimentación por encima del complejo de basamento cristalino.

Hay mucho debate acerca de exactamente cuando y como el estrecho pasaje oceánico que conectaba el océano pacifico y Caribe se cerró. Sin embargo, se acepta ampliamente que este cierre tuvo un efecto masivo en el clima y la fauna mundial. Esta conexión entre las Américas causó un gran intercambio biótico entre continentes. Además, los patrones de circulación global cambiaron, lo cual causó la glaciación en el hemisferio norte. El cambio en la circulación termohalina global debido al cierre del estrecho pasaje oceánico también tuvo un impacto importante en la evolución humana, y puede haber sido el catalizador para que los humanos se desarrollaran en una especie bípeda.

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Para terminar, mientras estuvimos en el BioMuseo, contactamos a alguien a quien le gustaría que hiciéramos un guión museográfico que hable de la historia de Panamá desde un punto de vista geológico. Adicionalmente, podríamos intentar organizar talleres e incluso viajes de campo al canal para personal del museo. El objetivo sería presentar la geología de la región con una explicación más comprensible, detallada, e interesante. Como este es un tema difícil y poco conocido, a ellos les gustaría contar con nuestra ayuda para crear interés en la gente. Los cuatro estamos muy emocionados, ya que gran parte de nuestra formación ha sido en geología. Los mantendremos informados acerca de este proceso.

Gracias y, por supuesto, Vamos Alligatores (Go Gators).

~Sonia~

Fossil Friday 3/20/15: A ghost shrimp

This Fossil Friday, I’m excited to share a fossil shrimp that was just described in a publication by FLMNH Postdoc Adiël Klompmaker and colleagues! Fossils of this new ghost shrimp, called Glypturus panamacanalensis, were found by M. D. Burkenroad in 1959, who collected from Holo-Pleistocene dredgings on the Amador and Farfan beaches at the entrance of the Panama Canal. Specimens of this shrimp have also been found in Florida and Cuba, and modern members of the genus Glypturus live in the salty waters of the Western Atlantic, the Indian Ocean, the southwest Pacific, and the Red Sea.

Glypturus panamacanalensis propodus

UF 248032, the outer and inner side of the right propodus of Glypturus panamacanalensis. The propodus consists of the “palm” and the fixed finger. (Excerpted from Klompmaker et al. 2015)

Glypturus acanthochirus

A modern Glypturus acanthochirus. (Photo courtesy of the Smithsonian Institution)

Shrimp, along with crabs and lobsters, are decapods (Phylum Arthropoda, Class Malacostraca, Order Decapoda). Decapods commonly have differently sized claws, referred to as major propodi and minor propodi. The larger major propodus is used for crushing while the smaller, sharper minor propodus is used for cutting.

Be sure to check out the paper on this new species of mud shrimp here!

Reference:

Adiël A. Klompmaker, Matúš Hyžný, Roger W. Portell & Michał Kowalewski (2015): Growth, inter- and intraspecific variation, palaeobiogeography, taphonomy and systematics of the Cenozoic ghost shrimp Glypturus, Journal of Systematic Palaeontology, DOI:10.1080/14772019.2015.1009505

Panama Trip and Squirrel Fossils

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.

Nathan doing what he does best!

Nathan doing what he does best!

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The view from Punta Culebra

Digging at Las Cascadas

Digging at Las Cascadas

Since being back in Florida I have been working on my research on fossil squirrels from Panama and Florida. I am interested in analyzing the postcrania of the genus Petauristodon in order to reconstruct locomotor behavior. As of recent I’ve been going through the collections from the Thomas Farm locality in Florida looking for postcranial elements. Hopefully I will have interesting progress to report soon!

Spring Interns in the news.

Journalist Irlanda Sotillo and Photographer Maydeé Romero Sprang recently visited the DSC_0123Center for Tropical Paleoecology and Archeology (CTPA) of the Smithsonian Tropical Research Institute (STRI), and met the PCP-PIRE field interns. We told Irlanda about the field activities in the canal area and showed her several samples recently collected by the interns.

Irlanda was originally interested in the PCP-PIRE program and the research on Panamanian fossils, and became particularly curious on the daily work conditions in theDSC_0064 canal and how the interns adapted to Panama´s culture and environment. Irlanda´s note was published yesterday in the Panamanian newspaper La Prensa. This note highlights the work of interns and researchers along the Panama Canal, and also invites to visit this blog.

La periodista Irlanda Sotillo y la Fotógrafa Maydeé Romero Sprang visitaron recientemente el Centro de Paleoecología y Arqueología Tropical (CTPA) del Instituto Smithsonian de Investigaciones Tropicales (STRI), y se reunieron con los pasantes de campo del proyecto PCP-PIRE. Le contamos a Irlanda acerca de las actividades de campo en el área del canal y le mostramos varias muestras recientemente recolectadas por los pasantes.

Irlanda estaba originalmente interesada en el programa PCP-PIRE y la investigación deDSC_0066 los fósiles panameños, y su curiosidad se enfocó de modo particular en las condiciones de trabajo que se encuentran a diario en el canal y en como los pasantes se adaptaron a la cultura y medio ambiente de Panamá. La nota periodística de Irlanda fue publicada ayer en el periódico panameño La Prensa. Esta nota resalta el trabajo de los pasantes e investigadores a lo largo del Canal de Panamá, y también invita a visitar este blog.

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A Brief Paleohistory of Panamá

(en español)

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Overlooking view of the canal from Zion Hill. Puente Centenario is visible in the distance.

As we have heard, the visiting group from the University of Florida just got back from a visit to Panamá, during which much time was spent in the canal searching for fossils.  The museum interns got their first taste of the Panamá sun! The trip went well, and many fossils were successfully uncovered.

In addition to fossil hunting, we were all able to visit the BioMuseo last week.  While there, we learned a little more about the geologic history of Panamá.  I enjoyed hearing more about the context of this important field area very much.  After all, these fossils that we so desperately search for are part of a larger story, which I would like to talk briefly about today: the paleohistory of Panamá and the great implications of the closing of the isthmus.

The exhibit at the BioMuseo started at the very beginning, a very good place to start…

Before Panamá was a solid land mass, the area was made up of a volcanic arc, in form of underwater volcanoes caused by tectonic subduction.  Pillow basalts, being the oldest rock found in Panamá, mark the beginning of this point in the paleohistory.  A series of volcanic and plutonic rocks formed during this whole process.  These underwater volcanoes eventually grew into small surfaced islands as they were uplifted.  This began the process of sedimentation on top of the complex crystalline basement.

There is much debate on exactly when and how the narrow seaway connecting the Pacific Ocean and Caribbean Sea closed.  However, it is widely accepted that this closing had a massive effect on global climate and fauna.  This connection between the Americas caused a massive biotic interchange between continents.  In addition, global circulation patterns changed, which caused northern hemisphere glaciation.   The change in global thermohaline circulation due to the closing of this narrow seaway also had a major impact on the evolution of humans, and might have been the catalyst for humans to develop into a bipedal species.

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Posing with some prehistoric animals at the BioMuseo.           [L-R: Sonia, Sophie, Adam]

In closing, while at the BioMuseo, we made a contact who would like for us to help make a narrative talking about the paleohistory of Panamá from a geologic standpoint.  In addition, we might try and organize workshops or even field trips to the canal for museum visitors.  The goal would be to present a more understandable, detailed, and interesting geologic account of the region.  As this is a more obscure and difficult topic, they would like our help to get people interested in it.  The four of us are very excited, as much of our training has been in geology.  We will keep you updated on this process!

Thanks and, of course, Go Gators.

~Sonia~

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References:

– BioMuseo, Panamá

– Montes, C. et al. Arc-continent collision and orocline formation: Closing of the Central American seaway. J. Geophys. Res. Solid Earth 1978–2012 117, (2012).

 

Fossil Friday 3/13/2015: A fossil shark tooth

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UF 242872, the tip of an upper tooth of Hemipristis serra. (Photo © VP FLMNH).

This Fossil Friday I would like to show you another shark from the Culebra Formation called Hemipristis serra. This specimen was found at the Hodge’s Hill site and is from the early Miocene. Fossils of this extinct shark are most common in warm-water marine deposits. Hemipristis elongatus, also known as the snaggletooth shark, is the only extant member of the genus and is found in tropical marine settings. Members of the genus Hemipristis are just a few of many that belong to the chondrichthyan Order Carcharhiniformes. Modern carcharhiniform sharks can be found in waters worldwide ranging from arctic to tropical and near shore to deep water.

To read more about this specimen, read the publication on it here. To read an entry in Fossils of Panama on Hemipristis serra from the Gatún Formation, click here.