Larisa R.G. DeSantis

Interests – Research – Students – Publications – Recent Press

 

Assistant Professor
larisa.desantis@vanderbilt.edu
DeSantis Lab Blog
Office: 5721 Science & Engineering Bldg
Phone: (615) 343-7831

Education

Ph.D. University of Florida, 2009
M.E.M. Yale University, 2003
B.S. University of California, Berkeley, 2000

Specializations

• Vertebrate Paleontology
• Paleoecology
• Paleoclimates

Curriculum Vitae

 

 

General Interests

Larisa DeSantis’s interdisciplinary research program focuses on understanding ecological dynamics through time, at a variety of spatial scales. She examines modern ecosystems to constrain environmental reconstructions of fossil localities, and uses the fossil record to inform ecologists and conservation biologists about faunal and flora responses to climate change. The integration of the disparate fields of ecology, paleontology, and geochemistry can synergistically improve understandings of long-term ecological dynamics. Specifically, her research goals include: 1) reconstructing ancient environments using modern ecological studies to help constrain paleoecological hypotheses; and, 2) understanding how mammalian communities and their floral environments have responded to climate change during the Cenozoic.

 

Current Research

Paleoecological tools including stable isotope, dental microwear, and morphology enable comparisons of modern and ancient terrestrial ecosystems across temporal boundaries. DeSantis integrates these tools to clarify how changing climates have affected mammals and their floral environments through time, globally. Her research program generally focuses on two major areas. The first area aims to clarify the paleoecology of forest environments through time. Tapirs, extant browsers occupying forest environments today, are model organisms for examining forest distributions over the last 55 million years and their modern ecology can help constrain paleoecological interpretations of late Cenozoic fossil localities where tapirs are abundant. Thus, DeSantis examines extant tapir populations throughout Central and South America to constrain ecological and climatic interpretations of fossil localities dominated by tapirs, primarily in the southeastern United States. She is also examining modern forest communities to “ground truth” floral carbon isotope variation in temperate forests.

3D photo simulation of the dental microwear of an extant grazing kangaroo. 
© Larisa R.G. DeSantis

DeSantis’s second area of research aims to inform ecologists and conservation biologists about the effects of long term climate change on mammalian communities and their environments. Currently, global climate change affects the composition and dynamics of mammalian communities and potentially increases their risk of extinction. However, the long-term effects of global warming on extinct mammals are less understood. Dietary reconstructions inferred from stable isotopes and dental microwear of fossil mammal teeth can document dietary niche partitioning, enable environmental inferences (e.g. grassland vs. forest), and allow for comparisons of aridity and/or relative seasonality over time. Through the analyses of fossil communities during the late Cenozoic, DeSantis assess the affects of climate change on mammals experiencing interglacial warming in North America to increased aridity in Australia. Although she focuses on ungulate and marsupial mammals, she is currently working on extending analyses to also include xenarthrans (i.e. sloths, armadillos, and relatives), carnivores, and small mammals.

Sampling an extant tapir for stable isotope analyses.
© Larisa R.G. DeSantis

 

What Students Do

Opportunities for M.S. and Ph.D. students include a broad range of projects with questions pertaining to either modern and/or ancient ecosystems. Masters students are encouraged to ask questions that can be appropriately answered using one or two paleoecological methods (e.g. stable isotope analyses, dental microwear texture analyses, morphological analyses, etc…), while Ph.D. students are encouraged to integrate multiple tools to answer interdisciplinary questions. Potential projects likely include laboratory analyses of museum specimens and may incorporate field opportunities. Students are also encouraged to communicate the broader impacts of their research to the public. Masters students pursing paleoecological research will be well prepared for advanced degrees in either biological or geological disciplines and careers ranging from environmental management to secondary education. Doctoral students are ideally suited to purse academic careers and/or engage in interdisciplinary professions that examine changing environments and climates.

I am currently looking for undergraduate volunteers for the Fall of 2011.

I am also considering new M.S. and Ph.D. students for the Fall of 2012.

 

Selected Publications

Dillehay, T. et. al. (DeSantis, L., 25th author). Cultural Complexity and Coastal Environment at Huaca Prieta, Peru from 9,000 to 4,500 years ago. PLoS ONE (In review)

Feranec, R.S., DeSantis, L.R.G.  Using carbon isotopes to determine carnivore prey preferences during the Pleistocene of Florida.  Palaeogeography, Palaeoclimatology, Palaeoecology(In revision) 

DeSantis, L.R.G.  Stable isotope ecology of extant tapirs from the Americas.  Biotropica  (In press) 

MacFadden, B.J., DeSantis, L.R.G., Labs Hochstein, J., Kamenov, G.D.  2010.  Physical properties, geochemistry, and diagenesis of xenarthran teeth: prospects for interpreting the paleoecology of extinct species.  Palaeogeography, Palaeoclimatology, Palaeoecology 291: 180-189

Schubert, B.W., Ungar, P.S., DeSantis, L.R.G.  2010.  Carnassial microwear and dietary behaviour in large carnivorans.  Journal of Zoology 280: 257-263

Prideaux, G.J., Ayliffe, L.K., DeSantis, L.R.G., Schubert, B.W., Murray, P.F., Gagan, M.K., Cerling, T.E.  2009.  Extinction implications of a chenopod browse diet for a giant Pleistocene kangaroo.  PNAS 106: 11646-11650. 

DeSantis, L.R.G., Feranec, R.S., MacFadden, B.J.  2009.  Effects of interglacial warming on ancient mammalian communities and their environments.  PLoS ONE 4: e5750

DeSantis, L.R.G.  2009.  Teaching evolution through inquiry-based lessons of uncontroversial science.  The American Biology Teacher 71(2): 106-111

DeSantis, L.R.G.  2009.  Straight from the mouths of horses and tapirs: using fossil teeth to clarify how ancient environments have changed over time.  Science Scope 32(5): 18-24    

DeSantis, L.R.G., Wallace, S.C.  2008.  Neogene forest from the Appalachians of Tennessee, USA: geochemical evidence from fossil mammal teeth.  Palaeogeography, Palaeoclimatology, Palaeoecology 266: 59-68

DeSantis, L.R.G., MacFadden, B.J.  2007.  Identifying forested environments in Deep Time using fossil tapirs: evidence from evolutionary morphology and stable isotopes.  Courier Forschungsinstitut Senckenberg 258: 147-157 (Special Issue: Advances in Angiosperm Paleobotany and Paleoclimatic Reconstruction – Contributions Honoring David L. Dilcher and Jack A. Wolfe)

DeSantis, L.R.G., Bhotika, S., Putz, F.E., Williams, K.  2007.  Sea-level rise and drought interactions accelerate declines on the Gulf Coast of Florida, USA.  Global Change Biology 13: 2349-2360

DeSantis, L.R.G.  2007.  Clarifying tropical cyclone activity in centuries past.  Science Teacher 74(6): 78-84

 

Recent Press

Human role in big kangaroo demise - BBC News

Climate change? Big mammals may be flexible - Discovery News / msNBC

Ancient Mammals Not So Finicky - ScienceNOW Daily News

Fossil Teeth Hint at Animal Adaptation to Global Warming - Wired Science