Fossil Friday 1/15/16: A camel mandible

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UF 254113, the right mandible of Aguascalientia minuta. The left mandible of this particular individual (not shown here) was also recovered and has the same catalog number. Photo © VP FLMNH.

This week’s Fossil Friday is the mandible of the camel Aguascalientia minuta. This specimen was found at the Lirio Norte Graben site in the Las Cascadas Formation and is early Miocene in age. This fossil camel species is the smallest known floridatraguline (Family Floridatragulinae).

To learn more about this specimen, read the publication on it here. Also, be sure to check out another floridatraguline from Panama (Aguascalientia panamaensis) at one of our previous Fossil Friday posts here.

Reference

Rincon, A., Bloch, J.I., Suarez, C., MacFadden, B.J., and Jaramillo, C. 2012 New Floridatragulines (Mammalia, Camelidae) From The Early Miocene Las Cascadas Formation, Panama. Journal of Vertebrate Paleontology, 32: 456-475.
www.dx.doi.org/10.1080/02724634.2012.635736

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Fossil Friday 9/4/15: A small protoceratine

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UF 271625, the left mandible of Paratoceras orarius. Photo © VP FLMNH.

For this week’s Fossil Friday, we have a newly identified protoceratid called Paratoceras orarius. This protoceratid is the smallest member of the informal protoceratid subfamily “Protoceratinae.” This specimen was found in the upper Culebra Formation and is early Miocene (He1, or early Hemingfordian North American Land Mammal Age [NALMA]). The specific name “orarius” means “estuarine” or “coastal,” which is the inferred environment for the upper Culebra.

If you would like to learn more about this specimen, read the publication that includes it below! Be sure to check out our other Fossil Friday protoceratid, which was renamed as a new species (Paratoceras coatesi) according to the same paper!

Reference:

Rincon, A. F., Bloch, J. I., MacFadden, B. J., Jaramillo, C. A. 2015. New early Miocene protoceratids (Mammalia, Artiodactyla) from Panama. Journal of Vertebrate Paleontology. doi:10.1080/02724634.2015.970688. New early Miocene protoceratids (Mammalia, Artiodactyla) from Panama.

All the Small Things

Over the past couple of weeks I’ve been working on several smaller projects around the lab that have included identifying specimens from the Gatun formation, washing samples of Pacific Muck in the screen washing room, and unpacking specimen from several storage boxes in the lab. Continue reading

Fossil Friday 5/15/15: A kogiid whale

UF280000, a dorsal view of the skull of Nanokogia isthmia

UF280000, a dorsal view of the skull of Nanokogia isthmia. (Photo excerpted from Velez-Juarbe et al. 2015)

For this Fossil Friday we have a whale of a discovery to share, specifically the skull of a kogiid whale. Nanokogia isthmia is the first fossil kogiid whale found in the Central America and Caribbean region. It was collected from the Piña Facies of the Chagres Formation and is about 7.5 million years old (late Miocene). Kogiids are a family of odontocete (toothed) whales and are represented by only two species in the modern day, Kogia breviceps and Kogia sima. Although kogiids can be found in waters worldwide, they are quite rare both today and in the fossil record. This discovery of a kogiid whale in Panama helps show that these whales were a part of Neotropical marine communities since at least the late Miocene.

The description of this discovery was written by former PCP PIRE postdocs Jorge Velez-Juarbe (first author), Aaron Wood, and Austin Hendy and former STRI fellow Carlos De Gracia. Be sure to check out their publication on this fascinating find here.

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A photo of a modern Kogia breviceps, the pygmy sperm whale. (Photo courtesy of the National Oceanic and Atmospheric Administration)

Reference:

Velez-Juarbe, J., Wood, A. R., De Gracia, C., Hendy, A. J. W. (2015) Evolutionary Patterns among Living and Fossil Kogiid Sperm Whales: Evidence from the Neogene of Central America. PLoS ONE 10(4): e0123909. doi:10.1371/journal.pone.0123909

Fossil Friday 5/8/15: Barnacles!

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The shell of the modern muricid gastropod Murex globusus (left) and UF 250804, a fossil barnacle with an incomplete drill hole from the Armuelles Formation of Panama. (M. globusus photo courtesy of Kevmin, barnacle photo excerpted from Klompmaker et al. 2015)

This Fossil Friday we have a barnacle from the Pleistocene Armuelles Formation. Barnacles are crustacean arthropods (Phylum Arthropoda, Subphylum Crustacea), so they are somewhat related to crabs and lobsters. Something special about this particular barnacle is the incomplete hole in one of its plates. This barnacle was preyed upon by a drilling predator just like many other shelled marine invertebrates, such as clams, snails and crabs, to name a few. Possible culprits behind these drill holes, which are still around and continue to drill today, are muricid snails (see photo) and octopods.

To read more about this specimen and barnacles as victims of drilling predators, check out the publication here.

Reference:

Klompmaker, A.A., R.W. Portell, S.E. Lad, and M. Kowalewski. 2015. The fossil record of drilling predation on barnacles. Palaeogeography, Palaeoclimatology, Palaeoecology 426: 95–111. doi:10.1016/j.palaeo.2015.02.035

Smithsonian’s Panama Debate Fueled by Zircon Dating | Newsdesk

Ocean currents before the formation of the Isthmus of Panama. Photo Smithsonian Tropical Research Institute

Ocean currents before the formation of the Isthmus of Panama. (Photo © Smithsonian Tropical Research Institute)

Camilo Montes and colleagues have made exciting discoveries about the dating of the rise of the Isthmus of Panama using detrital zircons! Visit the following link to the Smithsonian’s website to read the press release! Smithsonian’s Panama Debate Fueled by Zircon Dating | Newsdesk.

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. Continue reading

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.

Cleaning up after spring break

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!

Jeremy with his humerus at Centenario 2 of the Cucaracha Formation

Jeremy with his humerus at Centenario 2 of the Cucaracha Formation

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.

When we started...

When we started…

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.

Our newly restored locality!

Our newly restored locality!

Stay tuned for more! And Go Gators!