Skip to main content.

Smithsonian National Museum of Natural History

Department of Paleobiology

  • Nicholas D. Pyenson
  • Curator of Fossil Marine Mammals
  • Phone:   202-633-1366
  • Fax:   202-786-2832
  • E-mail Address:   pyensonn
  • 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.


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 S., 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, The Anatomical Record, 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)

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

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

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

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, The Journal of Experimental Biology, 216:2691-2701

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

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

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

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

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

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

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

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

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

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

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

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

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

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