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Seth Finnegan
Curator/Assistant Professor, Integrative Biology

Seth Finnegan


Phone: (510) 664-9916

Web page:

His research: "My research interests are all over the place, but temporally I tend to focus on the Paleozoic, and especially the Ordovician Period. Most phyla make a relatively rapid appearance in the fossil record in the Cambrian, but it's in the mid-Ordovician when you see a big increase in diversity. During this period, the types of marine ecosystems that generally characterize much of the rest of the Paleozoic are established. But then, the Ordovician ends with the first major mass extinction. So the Ordovician is a very useful period to focus on because I'm interested in how you add diversity to ecosystems and what happens to the structure and function of those ecosystems when you take it away.

"In a recent paper in Nature, paleontologists and ecologists argue that the current anthropogenically driven mass extinction may be pushing global ecosystems towards a state shift. The late Ordovician mass extinction is interesting because it's a case where you remove huge numbers of species and genera — even families — and it doesn't make much difference in terms of the marine ecosystems. Silurian marine ecosystems look very much like those of the Ordovician! This would appear to be a really big mass extinction that actually does not result in a state shift. I find it quite interesting to compare that event with something like the Permo-Triassic extinction or what we may be heading into now."

Questions: "We can look at extinction events in terms of sheer numbers of groups that go extinct, but it's only a single dimension of diversity loss. What's interesting to me is to ask which particular things go extinct and which ones don't? How are those extinctions distributed, not just phylogenetically but ecologically? What are the determinants of extinction risk for a particular event? How do those change through time and how does that then propagate forward to determine the structure of future ecosystems?"

What he loves about research: "I really get excited about seeing fossils in the context of the rocks in the field. A drawer of museum specimens can be very interesting, but seeing those fossils in the context of the sedimentary rocks recording the environment in which they lived is a much richer experience. There's no substitute for really getting out and grappling with the taphonomic aspects — thinking about how this information is being filtered through the record, and also what the rocks are telling us about what really happened here. So field work is great both intellectually and — I won't lie — it's fun to be able to travel!

"And of course there's a real thrill when you actually figure something out — when it clicks. It's what keeps you coming back."


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

Finnegan, S., Heim N.A., Peters S.E., and 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

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

Rohrssen, M., G.D. Love, W.W. Fischer, S. Finnegan, and D.A. Fike. 2012. Lipid biomarkers record fundamental changes in the microbial community structure of tropical seas during the Late Ordovician Hirnantian glaciation. Geology, published online November 6.

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. Paleobiology 37(2): 252-269

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

Finnegan, S., Peters, S., and Fischer, W.W. 2011. Late Ordovician-Early Silurian selective extinction patterns in Laurentia and their relationship to climate change, In: J.C. Gutiérrez-Marco, I. Rábano, D. García-Bellido (editors), Ordovician of the World, Cuadernos del Museo Geominero, 14, Instituto Geologico y Minero de España, Madrid, 155-159

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

Payne, J.L., C.R. McClain, A.G. Boyer, J.H. Brown, S. Finnegan, M. Kowalewski, R.A. Krause Jr., S.K. Lyons, D.W. McShea, P.M. Novack-Gottshall, F.A. Smith, P. Spaeth, J.A. Stempien and S.C. Wang. 2011. The evolutionary consequences of oxygenic photosynthesis: a body size perspective. Photosynthesis Research 107(1):37-57

Kowalewski, M., and S. Finnegan. 2010. Theoretical diversity of the marine biosphere. Paleobiology 36(1):1-15.

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

Bennington, J.B., W.A. DiMichele, C. Badgley, R.K. Bambach, P. Barrett, A.K. Behrensmeyer, R. Bobe, R. Burnham, T. Daeschler, J. Van Dam, J. Eronen, D.H. Erwin, S. Finnegan, S. Holland, G. Hunt, D. Jablonski, S.T. Jackson, B. Jacobs, S.M. Kidwell, P. Koch, M. Kowalewski, C. Labandeira, C. Looy, S.K. Lyons, P.M. Novack-Gottshall, R. Potts, P. Roopnarine, C. Strömberg, H. Sues, P. Wagner, P. Wilf, and S. Wing. 2009. Critical issues of scale in paleoecology. Palaios 24(1):1-4

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.

Sumrall, C.D., J. Sprinkle, S. Pruss, and S. Finnegan. 2009. Cardiocystella, a new cornute stylophoran from the Upper Cambrian Whipple Cave Formation, eastern Nevada, USA. Journal of Paleontology 83(2):307-312.

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.

Payne, J.L., and S. Finnegan. 2007. The effect of geographic range on extinction risk during background and mass extinction. Proceedings of the National Academy of Sciences 104(25):10506-10511.

Payne, J.L., and S. Finnegan. 2006. Controls on marine animal biomass through geological time. Geobiology 4(1):1-10.

Finnegan, S., and M.L. Droser. 2005. Relative and absolute abundance of trilobites and rhynchonelliform brachiopods across the Lower/Middle Ordovician boundary, eastern Basin and Range. Paleobiology 31(3):480-502.

Droser, M.L., and S. Finnegan. 2003. The Ordovician Radiation: a follow-up to the Cambrian explosion? Integrative and Comparative Biology 43(1):178-184.

Finnegan, S., and M.L. Droser. 2003. Paleoecological significance of the Ibexian-Whiterockian (Lower-Middle Ordovician) boundary in the Great Basin, western U.S. Pp. 297-302. In G. L. Albanesi, M. S. Beresi, and S. H. Peralta, (editors) Ordovician from the Andes: Proceedings of the 9th International Symposium on the Ordovician System.