Seth Finnegan

Seth Finnegan

Associate Professor

Phone: (510) 664-9916
Lab Webpage:

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Research Description

I am broadly interested in the processes that have shaped the composition of the marine biota and the development of marine ecosystems from the origin of animals in the late Neoproterozoic to the present day.  Research in my lab integrates data from a variety of sources including field observations, lab work, and literature databases to ask and answer questions about the nature of organism-environment interactions through time. 

I am particularly interested in (1) Patterns of extinction selectivity, and what they can tell us about the changing drivers of the extinction process and how differential extinction has shaped evolution through time, (2) Using environmental proxy data (stable isotopes, biomarkers, stratigraphy) to understand the physical context of major evolutionary and ecological events recorded by the fossil record, and (3) Developing taxon-free methods to reconstruct the structure and function of marine ecosystems (e.g. as energy- and nutrient-exchange networks) through time. 

Much of my recent and continuing work focuses on the Ordovician Period (488 to 444 million years ago) because it is widely agreed (by me) to be the most interesting interval in Earth history, including as it does a broad-based and very rapid global biodiversification and a major mass extinction.  However, I enjoy distractions and new problems and encourage students to develop independent projects on any topic, provided that it is one on which I feel that I can provide competent advising.

Selected Publications

Finnegan S., Fike, D.A., Jones, D.S, and Fischer W.W. 2012. A Temperature-dependent feedback on the magnitude of carbon isotope excursions. Geoscience Canada  39: 122-131

Harnik, P.G., Lotze, H.K., Anderson, S.C., Finkel, Z.V., Finnegan, S., Lindberg, D.R., Liow, L.H., Lockwood, R., McClain, C.R., McGuire, J.L., O’Dea, A., Pandolfi, J.M., Simpson, C., and Tittensor, D.P. 2012. Extinctions in ancient and modern seas. Trends in Ecology and Evolution 27(11):608-17

Rohrssen, M.,  Love, G.D., Fischer, W.W., Finnegan, S., and Fike, D.A. 2012. Lipid biomarkers record fundamental changes in the microbial community structure of tropical seas during the Late Ordovician Hirnantian glaciation. Geology, doi: 10.1130/G33671.1

Finnegan S., Heim N.A., Peters S.E., Fischer W.W. 2012. Climate change and the selective signature of the Late Ordovician mass extinction. Proceedings of the National Academy of Sciences 109(18): 6829-6834

Finnegan, S., C.R. McClain, M.A. Kosnik, and J.L. Payne. 2011. Escargots through time: comparative energetics of marine gastropod assemblages before and after the Mesozoic Marine Revolution. 2011. Paleobiology 37(2): 252-269

Jones, D.S., D.A. Fike, S. Finnegan, W.W. Fischer, D.P. Schrag and D. McCay. 2011. Terminal Ordovician carbon isotope stratigraphy and glacioeustatic sea-level change across Anticosti Island (Québec, Canada).  Geological Society of America Bulletin 123(7-8): 1645-1664

Finnegan, S., K. Bergmann, J.M. Eiler, D.S. Jones, D.A. Fike, I. Eisenman, N.C. Hughes, A.K. Tripati and W.W. Fischer.  2011. The magnitude and duration of Late Ordovician-Early Silurian glaciation. Science 331(6019):903-906

Pruss, S., S. Finnegan, W. Fischer, and A.H. Knoll. 2010. Carbonates in skeleton-poor seas: new insights from Cambrian and Ordovician strata of Laurentia. Palaios 25(2):73-84

Payne, J. L., A. G. Boyer, J. H. Brown, S. Finnegan, M. Kowalewski, R. A. Krause, Jr., S. K. Lyons, C. R. McClain, D. W. McShea, P. M. Novack-Gottshall, F. A. Smith, J. A. Stempien, and S. C. Wang. 2009. Two-phase increase in the maximum size of life over 3.5 billion years reflects biological innovation and environmental opportunity. Proceedings of the National Academy of Sciences 106(1):24-27.

Finnegan, S., and M.L. Droser. 2008a. Body size, energetics, and the Ordovician restructuring of marine ecosystems. Paleobiology 34(3):342-359.

Finnegan, S., and M.L. Droser. 2008b. Reworking diversity: effects of storm deposition on evenness and sampled richness, Ordovician of the Basin and Range, Utah and Nevada, USA. Palaios 23(2):87-96.

Finnegan, S., J.L. Payne, and S.C. Wang. 2008. The Red Queen revisited: reevaluating the age selectivity of Phanerozoic marine genus extinctions. Paleobiology 34(3):318-341.