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Department of Paleobiology

  • Nicholas D. Pyenson
  • Curator of Fossil Marine Mammals
  • Phone:   202-633-1366
  • Fax:   202-786-2832
  • E-mail Address:   pyensonnat SI dot edu
  • Mailing Address:
    Smithsonian Institution
    PO Box 37012, MRC 121
    Washington, DC 20013-7012
  • Shipping Address:
    Smithsonian Institution
    National Museum of Natural History
    10th & Constitution NW
    Washington, DC 20560-0121


Ph.D. University of California, Berkeley, 2008
B.S. Emory University, 2002
A.A. Oxford College of Emory University, 2000

Research Interests

I study the paleobiology of marine mammals, and, more broadly, of other marine tetrapods. The evolution of whales, for example, is just one case of several mammalian lineages that have made a series of independent transitions from terrestrial to marine lifestyles at different times during the past 55 million years. Each group of marine mammals has undergone dramatic evolutionary transformations from their terrestrial ancestries, with attendant modifications to multiple anatomical, behavioral and ecological systems. These multiple transitions provide a series of evolutionary comparisons that form the basis for understanding how marine mammals have diversified in the oceans. By extension, I am also interested in the evolutionary and ecological histories of other marine tetrapods -- four-limbed animals that have that made the great transition from life on land to life in the sea. The scope of these investigations primarily focuses on marine rocks from the Cenozoic, including a broad array of field localities in both the Northern and Southern hemispheres.

Also, see my Pyenson Lab blog and my Google Scholar page.


Peredo, Carlos Mauricio and Pyenson, Nicholas D. 2018. Salishicetus meadi, a new aetiocetid from the late Oligocene of Washington State and implications for feeding transitions in early mysticete evolution, Royal Society Open Science, 5(4):172336-172336

Peredo, Carlos Mauricio, Peredo, Julio S. and Pyenson, Nicholas D. 2018. Convergence on dental simplification in the evolution of whales, Paleobiology, ():1-10

Slater, Graham J., Goldbogen, Jeremy A. and Pyenson, Nicholas D. 2017. Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics, Proceedings of the Royal Society B: Biological Sciences, 284(1855):-

Pyenson, Nicholas D. 2017. The Ecological Rise of Whales Chronicled by the Fossil Record, Current Biology, 27(11):R558-R564

Fleming, Alyson H. and Pyenson, Nicholas D. 2017. How to Produce Translational Research to Guide Arctic Policy, Bioscience, 67(6):490-493

Boersma, Alexandra T., McCurry, Matthew R. and Pyenson, Nicholas D. 2017. A new fossil dolphin Dilophodelphis fordycei provides insight into the evolution of supraorbital crests in Platanistoidea (Mammalia, Cetacea), Royal Society Open Science, 4(5):-

Peredo, Carlos Mauricio, Pyenson, Nicholas D., Uhen, Mark D. and Marshall, Christopher D. 2017. Alveoli, teeth, and tooth loss: Understanding the homology of internal mandibular structures in mysticete cetaceans, PloS One, 12(5):1-26

Peredo, Carlos Mauricio and Pyenson, Nicholas D. 2017. Decoupling tooth loss from the evolution of baleen in whales, Frontiers in Marine Science, ():-

Shadwick, Robert E., Goldbogen, Jeremy A., Pyenson, Nicholas D. and Whale, James C. A. 2017. Structure and Function in the Lunge Feeding Apparatus: Mechanical Properties of the Fin Whale Mandible, Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology, 300(11):1953-1962

Valenzuela-Toro, Ana, Pyenson, Nicholas D., Gutstein, Carolina S. and Suárez, Mario E. 2016. A new dwarf seal from the late Neogene of South America and the evolution of pinnipeds in the southern hemisphere, Papers in Palaeontology, 2(1):101-115

Le Roux, Jacobus P., Achurra, Luciano, Henríquez, Álvaro, Carreño, Catalina, Rivera, Huber, Suárez, Mario E., Ishman, Scott E., Pyenson, Nicholas D. and Gutstein, Carolina S. 2016. Oroclinal bending of the Juan Fernández Ridge suggested by geohistory analysis of the Bahía Inglesa Formation, north-central Chile, Sedimentary Geology, 333():32-49

Pyenson, Nicholas D., Parham, James F. and Velez-Juarbe, Jorge. 2016. The dilemma of trade samples and the importance of museum vouchers-caveats from a study on the extinction of Steller's sea cow: a comment on Crerar et al. (2014), Biology Letters, 12(2):20150149-

O'Dea, Aaron, Lessios, Harilaos A., Coates, Anthony G., Eytan, Ron I., Restrepo-Moreno, Sergio, Cione, Alberto L., Collins, Laurel S., de Queiroz, Alan, Farris, David W., Norris, Richard D., Stallard, Robert F., Woodburne, Michael O., Aguilera, Orangel, Aubry, Marie-Pierre, Berggren, William A., Budd, Ann F., Cozzuol, Mario A., Coppard, Simon E., Duque-Caro, Herman, Finnegan, Seth, Gasparini, German M., Grossman, Ethan L., Johnson, Kenneth G., Keigwin, Lloyd D., Knowlton, Nancy, et al. 2016. Formation of the Isthmus of Panama, Science Advances, 2(8):-

Pyenson, Nicholas D. and Vermeij, Geerat J. 2016. The rise of ocean giants: maximum body size in Cenozoic marine mammals as an indicator for productivity in the Pacific and Atlantic Oceans, Biology Letters, 12(7):-

Boersma, Alexandra T. and Pyenson, Nicholas D. 2016. Arktocara yakataga, a new fossil odontocete (Mammalia, Cetacea) from the Oligocene of Alaska and the antiquity of Platanistoidea, PeerJ, 4():-

Yamato, Maya, Khidas, Kamal, Pyenson, Nicholas D., Fordyce, R. Ewan and Mead, James G. 2016. Extensively remodeled, fractured cetacean tympanic bullae show that whales can survive traumatic injury to the ears, Journal of anatomy, 228(1):125-136

Boersma, Alexandra T. and Pyenson, Nicholas D. 2015. Albicetus oxymycterus, a New Generic Name and Redescription of a Basal Physeteroid (Mammalia, Cetacea) from the Miocene of California, and the Evolution of Body Size in Sperm Whales, PLoS ONE, 10(12):1-32

Yamato, Maya and Pyenson, Nicholas D. 2015. Early development and orientation of the acoustic funnel provides insight into the evolution of sound reception pathways in cetaceans, PloS One, 10(3):1-15

Kelley, Neil P. and Pyenson, Nicholas D. 2015. Evolutionary innovation and ecology in marine tetrapods from the Triassic to the Anthropocene, Science, 348(6232):-

Vogl, A. W., Lillie, Margo A., Piscitelli, Marina A., Goldbogen, Jeremy A., Pyenson, Nicholas D. and Shadwick, Robert E. 2015. Stretchy nerves are an essential component of the extreme feeding mechanism of rorqual whales, Current biology, 25(9):R360-R361

Goldbogen, Jeremy, Shadwick, Robert, Lillie, Margo, Piscitelli, Marina, Potvin, Jean, Pyenson, Nicholas D. and Vogl, A. W. 2015. Using morphology to infer physiology: case studies on rorqual whales (Balaenopteridae), Canadian journal of zoology, 93(9):687-700

Pyenson, Nicholas D., Vélez-Juarbe, Jorge, Gutstein, Carolina S., Little, Holly, Vigil, Dioselina and O'Dea, Aaron. 2015. Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of 'river dolphins' in the Americas, PeerJ, 3():1-50

Gutstein, Carolina S., Figueroa-Bravo, Constanza P., Pyenson, Nicholas D., Yury-Yañez, Roberto E., Cozzuol, Mario A. and Canals, Mauricio. 2014. High frequency echolocation, ear morphology, and the marine-freshwater transition: A comparative study of extant and extinct toothed whales, Palaeogeography palaeoclimatology palaeoecology, 400():62-74

Pyenson, Nicholas D., Kelley, Neil P. and Parham, James F. 2014. Marine tetrapod macroevolution: Physical and biological drivers on 250 Ma of invasions and evolution in ocean ecosystems, Palaeogeography palaeoclimatology palaeoecology, 400():1-8

Gutstein, Carolina Simon, Cozzuol, Mario Alberto and Pyenson, Nicholas D. 2014. The Antiquity of Riverine Adaptations in Iniidae (Cetacea, Odontoceti) Documented by a Humerus from the Late Miocene of the Ituzaingó Formation, Argentina, Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology, 297(6):1096-1102

Pyenson, Nicholas D., Gutstein, Carolina S., Parham, James F., Le Roux, Jacobus P., Chavarria, Catalina C., Little, Holly, Metallo, Adam, Rossi, Vincent, Valenzuela-Toro, Ana M., Velez-Juarbe, Jorge, Santelli, Cara M., Rogers, David R., Cozzuol, Mario A. and Suarez, Mario E. 2014. Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea, Proceedings of the Royal Society B: Biological Sciences, 281(1781)

Pyenson, Nicholas D., Goldbogen, Jeremy A. and Shadwick, Robert E. 2013. Mandible allometry in extant and fossil Balaenopteridae (Cetacea: Mammalia): the largest vertebrate skeletal element and its role in rorqual lunge feeding, Biological Journal of the Linnean Society, 108(3):586-599

Valenzuela-Toro, Ana M., Gutstein, Carolina S., Varas-Malca, Rafael M., Suarez, Mario E. and Pyenson, Nicholas D. 2013. Pinniped Turnover in the South Pacific Ocean: New Evidence from the Plio-Pleistocene of the Atacama Desert, Chile, Journal of Vertebrate Paleontology, 33(1):216-223

Pyenson, Nicholas D. 2013. Ecology and Conservation of the Sirenia: Dugongs and Manatees by Helene Marsh, Thomas J. O'Shea, and John E. Reynolds, The Quarterly review of biology, 88(1):42-43

Shadwick, Robert E., Goldbogen, Jeremy A., Potvin, Jean, Pyenson, Nicholas D. and Vogl, Wayne. 2013. Novel muscle and connective tissue design enables high extensibility and controls engulfment volume in lunge-feeding rorqual whales, Journal of experimental biology, 216():2691-2701

Noakes, Scott E., Pyenson, Nicholas D. and McFall, Greg. 2013. Late Pleistocene gray whales (Eschrichtius robustus) offshore Georgia, U.S.A., and the antiquity of gray whale migration in the North Atlantic Ocean, Palaeogeography palaeoclimatology palaeoecology, 392():502-509

Debey, Lauren B. and Pyenson, Nicholas D. 2013. Osteological correlates and phylogenetic analysis of deep diving in living and extinct pinnipeds: What good are big eyes?, Marine Mammal Science, 29(1):48-83

Pyenson, Nicholas D., Goldbogen, Jeremy A., Vogl, A. Wayne, Szathmary, Gabor, Drake, Richard L. and Shadwick, Robert E. 2012. Discovery of a sensory organ that coordinates lunge feeding in rorqual whales, Nature, 485(7399):498-501

Goldbogen, Jeremy A., Calambokidis, John, Croll, Donald A., McKenna, Megan F., Olseson, Erin, Potvin, Jean, Pyenson, Nicholas D., Schorr, Greg, Shadwick, Robert E. and Tershy, Bernie R. 2012. Scaling of lunge feeding performance in rorqual whales: mass-specific energy expenditure increases with body size and progressively limits diving capacity, Functional Ecology, 26(1):216-226

Velez-Juarbe, Jorge, Domning, Daryl P. and Pyenson, Nicholas D. 2012. Iterative Evolution of Sympatric Seacow (Dugongidae, Sirenia) Assemblages during the Past ~26 Million Years, PLoS ONE, 7(2):1-8

Vélez-Juarbe, Jorge and Pyenson, Nicholas D. 2012. Bohaskaia monodontoides, a new monodontid (Cetacea, Odontoceti, Delphinoidea) from the Pliocene of the western North Atlantic Ocean, Journal of Vertebrate Paleontology, 32(2):476-484

Pyenson, Nicholas D. and Sponberg, Simon N. 2011. Reconstructing body size in extinct crown Cetacea (Neoceti) using allometry, phylogenetic methods and tests from the fossil record, Journal of Mammalian Evolution, 18(4):269-288

Pyenson, Nicholas D. and Lindberg, David R. 2011. What Happened to Gray Whales during the Pleistocene? The Ecological Impact of Sea-Level Change on Benthic Feeding Areas in the North Pacific Ocean, PLoS ONE, 6(7):1-14

Uhen, Mark D., Pyenson, Nicholas D., Devries, Thomas J., Urbina, Mario and Renne, Paul R. 2011. New Middle Eocene Whales from the Pisco Basin of Peru, Journal of Paleontology, 85(5):955-969

Pyenson, Nicholas D. 2011. The high fidelity of the cetacean stranding record: insights into measuring diversity by integrating taphonomy and macroecology, Proceedings of the Royal Society B: Biological Sciences, 278(1724):3608-3616

McKenna, Megan F., Cranford, Ted W., Berta, Annalisa and Pyenson, Nicholas D. 2011. Morphology of the odontocete melon and its implications for acoustic function, Marine Mammal Science, 28(4):690-713

Goldbogen, J. A., Calambokidis, J., Oleson, E., Potvin, J., Pyenson, Nicholas D., Schorr, G. and Shadwick, R. E. 2011. Mechanics, hydrodynamics and energetics of blue whale lunge feeding: efficiency dependence on krill density, Journal of Experimental Biology, 214(1):131-146

Parham, James F. and Pyenson, Nicholas D. 2010. New Sea Turtle from the Miocene of Peru and the Iterative Evolution of Feeding Ecomorphologies since the Cretaceous, Journal of Paleontology, 84(2):231-247

Pyenson, Nicholas D. 2010. Carcasses on the coastline: measuring the ecological fidelity of the cetacean stranding record in eastern North Pacific Ocean, Paleobiology, 36(3):453-480

Pyenson, Nicholas D., Irmis, Randall B. and Lipps, Jere H. 2010. Comment on "Climate, Critters, and Cetaceans: Cenozoic Drivers of the Evolution of Modern Whales", Science, 330(6001):178-

Uhen, M. D. and Pyenson, Nicholas D. 2007. Diversity estimates, biases, and historiographic effects: Resolving cetacean diversity in the tertiary, Palaeontologia Electronica, 10(2):11A-11A