Current Program: Ph.D. in Biology

M.S. in Geology, Michigan State University, 2001

B.S. in Geology, University of Illinois at Urbana-Champaign, 1999

My general research interest is functional morphology, the relationship between form and function, in extinct and extant organisms, especially in predator-prey systems. My primary tool for this is biomechanics, the application of quantitative engineering techniques to determine how organisms perform mechanical functions, the design of morphological systems, and the relationship of these to the organism's environment.

The goal of my dissertation is to explore the evolution of shark teeth in the context of functional morphology and biomechanics. Sharks have survived for 400 million years, no doubt due in part to the function and diversity of form of their feeding apparatuses. Studying the functional morphology of their teeth will not only fill in gaps about the roles that teeth play in feeding, but also will provide insight on the evolution of shark and vertebrate feeding, as sharks represent an early offshoot of vertebrate life. While asking how shark teeth work seems like a simple question with a simple answer (they cut, slice, tear, etc.), the issue is complicated by morphology. Sharks display a variety of tooth morphologies; presumably, different forms should have different functions. When you apply the question of tooth function to fossil sharks, the problem becomes even more complex, as teeth are often the only part that fossilizes. Very little is known about diet or the rest of the feeding apparatus in extinct species, unlike thier extant cousins. Paleontologists must reconstruct the entire life history and anatomy of a species based on little information.

This study consists of five integrated steps: (1) Performance testing of shark teeth in puncture (mimicking gripping of prey); (2) Performance testing of shark teeth in unidirectional draw (which mimics lateral head shaking behavior and drawing of the teeth through tissue); (3) Finite Element Analysis (FEA), to explore the effect of tooth shape on stress distribution within the teeth; (4) Nanoindentation to determine various material propterites of the components of shark teeth and (5) An evolutionary analysis of tooth form and function incorporating steps 1 and 2.

This study is being funded by the Tampa Bay Fossil Club and the American Elasmobranch Society.

• Using tooth measures to determine species specific bite patterns in sharks (in preparation)
• Evolution of gastropod shell ornamentation (with Dr. Gregory Herbert, Dept. of Geology)
• Evolution of radular teeth in carnivorous marine snails (with Dr. Gregory Herbert, Dept. of Geology)
• Geometry representation, modification and iterative design using RKEM (with Dr. Daniel Simkins, Dept. of Civil Engineering)

• The feeding kinematics of aerial capture in the silver arowana, Osteoglossum bichirhossum
• Examination of the Lilliput effect after mass extinctions (research project for mass extinctions course)
• Morphometric analysis of teeth from extant and fossil mako sharks (Isurus) - M.S. thesis, manuscript in preparation
• Kinematics and force production of the agonistic strike of the dark mantis, Gonodactylus curacoensis (Stomatopoda) - research project for course in physical biology
• The fauna and paleoecology of the Burlington Formation (Mississippian) of Missouri, with a focus on chondrichthyans - B.S. thesis
• Description of a new sauropod genus (Apatosaurus sp.) from the Morrison Formation of Wyoming and its implications on sauropod evolution (work in progress)

• Simkins, D.C., Collier, N., Juha, M. and L.B. Whitenack. 2008. A framework for studying the RKEM representation of discrete point sets. In: M. Griebel and M.A. Schweitzer (eds.), Lecture notes in Computational Science and Engineering, Meshfree Methods for Partial Differential Equations IV.  Springer Publishing, New York. Pp. 301-315.
• Motta, P.J., Hueter, R.E., Tricas, T.C., Summers, A.P., Huber, D.R., Lowry, D., Mara, K.R., Matott, M.P. Whitenack, L.B., and A.P. Wintzer, 2008. Functional morphology of the feeding apparatus, feeding constraint and suction performance in the nurse shark, Ginglymostoma cirratum. Journal of Morphology 269: 1041-1055.
• Simkins, D.C., A. Kumar, N. Collier, and L.B. Whitenack, 2007. "Geometry representation, modification, and interative design using RKEM". Computer Methods in Applied Mechanics and Engineering. 196: 4304-4320.
• Simkins, D.C., L.B. Whitenack, and P.J. Motta, 2007. "A new engineering tool for 'what-if' finite element analysis in biology." Integrative and Comparative Biology.
• Whitenack, L.B., Simkins, D.C., and P.J. Motta, 2006. "Biology meets engineering: biomechanics and two-dimensional finite element analysis of carcharhinid teeth." American Elasmobranch Society Annual Meeting, 2006.
• Lowry, D., Wintzer, A., Matott, M., Whitenack, L.B., Huber, D., Dean, M., and P.J. Motta. 2005. Aerial and aquatic feeding in the silver arowana Osteoglossum bicirrhosum. Env. Biol. Fish. 73: 453-462.
• Whitenack, L.B.; T.J. Koob; and P.J. Motta, 2005. "A preliminary analysis of selachian tooth performance" Society for Integrative and Comparative Biology Annual Meeting.
• Whitenack, L.B., Elliott, D., and Brandenburg, J.P. 2002. "A case study in paleoecology from the Mississippian of Missouri, with a focus on chondrichthyan ichthyoliths." Transactions of the Missouri Academy of Sciences 36:11-14.
• Whitenack, L.B., 2001. "Using geometric morphometrics to distinguish teeth of extant and fossil Mako sharks." Journal of Vertebrate Paleontology, 21 (3 suppl): pp.113-114.
• Kowalke, R.S.; Whitenack, L.B.; Bakker, R.T., 1999. "A new dwarf species of Diplodocid, from the Morrison Formation (Jurassic) of Wyoming, and itscontradictions to sauropod evolution." Abstracts with Programs - Geological Society of America. 31(4).

• Society of Vertebrate Paleontology (SVP)
• American Elasmobranch Society (AES)
• Association for Women Geoscientists (AWS)
• Geological Society of America (GSA)
• Society for Integrative and Comparative Biology (SICB)
• Paleontology at Michigan State University
• The Tree of Life Web Project - look up information about phylogeny and biodiversity for almost anything
• Palaeos - a resource that gives an introduction to phylogeny and information and references for lots of organisms
• Biomesh - a resource for using finite element analysis in biology