Fossil Friday 5/6/16: A turtle dentary


UF 257195, the right dentary of a turtle, possibly Rhinoclemmys panamaensis (dorsal view). Photo © VP FLMNH.

Today’s Fossil Friday post is on the dentary, or lower jaw bone, of a turtle (possibly Rhinoclemmys panamaensis) found at the Hodges Microsite locality in the Cucaracha Formation of the Panama Canal Basin. The fossil is early Miocene in age. Its large size is notable as it is larger than any modern species of Rhinoclemmys.

To learn more about this specimen, read the publication on its discovery here.


Cadena, E., Bourque, J., Rincon, A., Bloch, J.I., Jaramillo, C., and MacFadden, B. 2012 New Turtles (Chelonia) from the Late Eocene through Late Miocene of the Panama Canal Basin. Journal of Paleontology 86: 539-557. doi: 10.1666/11-106.1


Fossil Friday 4/22/16: A New World Monkey

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UF 280128, the left upper first molar (M1) and holotype of Panamacebus transitus. Photo courtesy of Aldo Rincon, VP FLMNH and PCP PIRE.

This week’s Fossil Friday (and Earth Day) feature highlights an important new discovery that was just published in the journal Nature this week. Seven fossil teeth of a platyrrhine, or New World Monkey, named Panamacebus transitus were found at the Lirio Norte locality of Las Cascadas, and these teeth are the first known evidence of New World Monkeys in North America. The discovery of the teeth has also rewritten the history of mammalian dispersals from South America to North America, as they are the oldest record of a mammal dispersing from South America to North America with an age of 20.93 ± 0.17 Ma.

To learn more about this key discovery, read the publication on it here.


Bloch, J. I., Woodruff, E. D., Wood, A. R., Rincon, A. F., Harrington, A. R., Morgan, G. S., Foster, D. A., Montes, C., Jaramillo, C. A., Jud, N. A., Jones, D. S., and MacFadden, B. J. 2016. First North American Fossil Monkey and Early Miocene Tropical Biotic Interchange. Nature. doi:10.1038/nature17415

Fossil Friday 4/8/16: An artiodactyl tibia


UF 243751, an artiodactyl tibia. Photo © VP FLMNH.

For this week’s Fossil Friday post I present an artiodactyl tibia, perhaps one of a peccary (Family Tayassuidae) or a protoceratid (Family Protoceratidae). The curvature and the morphology of the end that articulates with the astragalus along with other features strongly suggests it belongs to an artiodactyl, however it was not found in association with other elements, like teeth, that could pinpoint an identification. This specimen was found in the upper Culebra Formation and is early Miocene in age.

To learn more about this specimen, read its description in the paper referenced below on peccaries found in Panama.


MacFadden, B.J., Kirby, M.X., Rincon, A., Montes, C., Moron, S., Strong, N., and Jaramillo, C. 2010. Extinct Peccary “Cynorca” occidentale (Tayassuidae) from the Miocene of Panama and Correlations to North America. Journal of Vertebrate Paleontology 84: 288-298. doi: 10.1666/09-064R.1

Fossil Friday 3/18/16: A gomphothere


UF 294322, a left lower third molar (m3) of the gomphothere Gomphotherium sp. Top: occlusal view, bottom: labial view. Figure modified from MacFadden et al. 2015.

On this week’s Fossil Friday I would like to show you a gomphothere tooth from Lake Alajuela (Alajuela Formation). Gomphotheres are extinct members of the mammalian Order Proboscidea (modern-day elephants are also members of this order). This specimen was found by Dr. John Turner in 1959 when he was a high school student. He discovered the tooth when he was at the Madden Boy Scout Camp (Lake Alajuela was formerly known as Lake Madden. The age of the specimen is difficult to discern, but it is likely mid- to late Miocene/early Pliocene in age. This specimen is the first known evidence of a pre-Pleistocene proboscidean in Panama.

To learn more about this specimen, read the paper detailing its discovery and taxonomy here.


MacFadden, B. J., Morgan, G. S., Jones, D. S., Rincon, A. F. 2015. Gomphothere proboscidean (Gomphotherium) from the late Neogene of Panama. Journal of Paleontology, 89(2): 360-365. doi: 10.1017/jpa.2014.31.

Dr. Jacquelyn Gill at UF

Today, PCP PIRE and other members of the University of Florida welcomed Dr. Jacquelyn Gill as she spoke about her research on extinction and climate change during the Pleistocene and how it can inform us about future climate change. Dr. Gill explained that large-bodied mammals helped buffer plants from changing climate and that megafaunal extinction may have caused plants to become more susceptible to the effects of climate change. Dr. Gill stressed that ecological interactions are strong factors in what decides a plant’s geographic range and that climate alone is not enough to explain geographic range – we should carefully consider these interactions when we are discussing conservation strategies for modern species. Dr. Gill is also an advocate for increasing diversity in the sciences.

To learn more about Dr. Gill’s research, follow her on Twitter and read about her lab on her webpage.

Fossil Friday 2/26/16: A boa constrictor


A modern Boa constrictor imperator, which is a subspecies of Boa constrictor. Photo © Esteban Alzate.

This week’s Fossil Friday post highlights fossil vertebrae of the boa constrictor (binomial name: Boa constrictor) found in the Las Cascadas (UF 255000) and Cucaracha Formations (UF 237882 and UF 237883). These specimens represent some of the oldest fossil vertebrates from South America dispersing to Central America at 19.3 million years ago.

For images of the fossil specimens and for more information on them, be sure to read the publication on them here.


Head, J., Rincon, A., Suarez, C., Montes, C., and Jaramillo, C. 2012 Fossil evidence for earliest Neogene American faunal interchange: Boa (Serpentes, Boinae) from the early Miocene of Panama. Journal of Vertebrate Paleontology 32: 1328-1334.

Fossil Friday 2/5/16: A hammerhead shark tooth


UF 232587, a hammerhead (Sphyrna sp.) shark tooth. Photo © VP FLMNH.

This week’s Fossil Friday post showcases a hammerhead (Sphyrna sp.) shark tooth. This particular specimen is from the Milwhite Gunn Farm Mine site in Florida, but fossil hammerhead teeth have been found in the Gatún Formation in Las Lomas and the Chucunaque Formation in Lago Bayano. Hammerhead sharks are found worldwide today but are only found in the Caribbean in the fossil record.

To learn more about fossil hammerhead sharks from Panama, check out the “Fossils of Panama” page on hammerhead shark teeth here.

Fossil Friday 1/29/16: A camel astragalus


UF 244163, the right astragalus of Aguascalientia panamaensis. Photo © VP FLMNH.

This week’s Fossil Friday features an astragalus of the camel Aguascalientia panamaensis. You can easily tell that these and other camels are artiodactyls (even-toed ungulates) from their double pulley astragalus. This specimen was found at the Lirio Norte site of the Las Cascadas Formation and is early Miocene in age.

Fossil Friday 1/15/16: A camel mandible


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.


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.

Fossil Friday 12/18/15: An extinct carcharhiniform shark

UF 262186, a lower tooth of Physogaleus contortus. Photo VP FLMNH.

UF 262186, a lower tooth of Physogaleus contortus. Photo © VP FLMNH.

This week’s Fossil Friday feature is the tooth of an extinct species of shark called Physogaleus contortus. This specimen was found in the Las Cascadas locality of the Culebra Formation and is early Miocene in age. This shark had a widespread distribution during the middle Miocene.

To learn more about this specimen, read the publication that includes it here.


Pimiento C., Gonzalez G., Hendy A., Jaramillo C., MacFadden B.J., Montes C., Suarez S.C., Shippritt M. 2013. Early Miocene chondrichthyans from the Culebra Formation, Panama: A window into marine vertebrate faunas before closure of the Central American Seaway. Journal of South American Earth Sciences 42: 159-170