David K. Watkins

Micropaleontology & Marine Geology

Professor of Earth & Atmospheric Sciences
214 Bessey Hall
University of Nebraska-Lincoln
Lincoln NE 68588-0340 USA
(phone) 1-402-472-2177
(fax) 1-402-472-4917
email: dwatkins@unl.edu

Jurassic of Portugal
Research Current Students Recent Graduates Recent Publications Courses Vita


Our lab was highlighted in the Fall 2010 issue (see page 4) of the Newsletter of the North American Micropaleontology Section (NAMS) of SEPM


Axopodorhabdus biramiculatus SEM
Cretarhabdus sp
Braarudosphaera stenorheta
Cenomanian chalk from Greenhorn Limestone of Kansas (SEM) with Axopodorhabdus biramiculatus.

Cretarhabdus conicus from Albian, western North Atlantic (SEM).

Braarudosphaera stenorheta from Albian, North Atlantic (cross-polarized light microscope)

My research is based on calcareous nannofossils, the smallest of all skeletal fossils routinely preserved in marine sediments. They are the main component of chalk (above). The rapid evolution of this group and their global distributions make them ideal biostratigraphic indicators for the Late Triassic through Recent. My students and I are currently pursuing projects to examine the variations in the biostratigraphy of both Cretaceous and Cenozoic nannofossils. Both probabilistic and deterministic methods of quantitative biostratigraphy are being used to define the most reliable bioevents. We are interested specifically in biostratigraphic variations that are related to differences in paleobiogeographic realm (both latitudinal and inter-oceanic) and to position of depositional systems relative to proximity to shore. We are currently working with records from the Cenozoic of Antarctica and the Southern Ocean, the Paleogene of the temperate regions, and the Cretaceous of North America and the world ocean.

Calcareous nannoplankton are controlled strongly by the nature of the surface water mass they inhabit. This relationship exerts a primary control on their distribution and especially their abundance in fossil assemblages. We are using statistical and numerical analysis to derive the relationships of nannofossil abundance to surface water fertility and paleotemperature as a way to examine paleoceanographic change. We are currently looking at these nannofossil assemblage dynamics to explore the nature of cyclic sedimentation in the Upper Cretaceous and Paleogene. Oceanic anoxic events (OAE) are of special interest in this regard, as the large-scale storage of organic carbon during these times, important in the generation of hydrocarbon source beds, was driven at least in part by major changes in surface-water fertility.

Major perturbations in oceanic surface-water characteristics, such as OAEs and thermal excursions, can drive the rapid evolution of the plankton. We are looking at the detailed evolution of several groups associated with these major oceanic perturbations in an effort to understand and document the mechanics of evolutionary change from a geological perspective. This includes work within a single species (e.g., Axopodorhabdus biramiculatus) and within major clades (e.g., Eiffellithus). By using astronomically tuned records, we are able to define the precise timing of speciation events and track the rise and fall of species during intervals of rapid global change.

Visit the UNL Paleontology website for more about our offerings.
Visit the International Nannoplankton Association website for more about nannofossils. INA logo


Current Graduate Students

Shamar Chin (Ph.D. student)
Shamar is examining the calcareous nannofossil paleoecology of the Upper Cretaeous from various locations.
Bryan Hermosillo

Bryan Hermosillo (M.S. student)
Bryan is examining the calcareous nannofossil biostratigraphy and paleoecology of the Coniacian stage from various locations.

william William Clark (M.S. student)
William is examining the nannofossil biostratigraphy of the Oligocene of the Gulf of Mexico and other areas.
Mauro Mauro Daniel Rodrigues Bruno (M.S. student at Instituto Tecnológico de Micropaleontologia, UNISINOS, Brazil)
Mauro is examining the nannofossil paleoceanography and biostratigraphy of the mid-Cretaceous South Atlantic Ocean.


Some Recent Graduates

Waheed Albasrawi (M.S. 2016)

Waheed examined the biostratigraphy and paleoecology of calcareous nannofossils from the lower Miocene of the tropical Atlantic with special emphasis on quantitative biostratigraphy. After graduation, Waheed joined Saudi Aramco as a nannofossil biostratigrapher.
Bobbi Brace (Ph.D. 2016)

Bobbi investigated the Pleistocene of the Sea of Japan and northern East China Sea for her dissertation. She recently sailed as a shipboard scientist (nannofossil paleontologist) on the JOIDES Resolution for IODP Expedition 346 of the Asian Monsoon. After graduation, Bobbi joined BHP Billiton as a nannofossil biostratigrapher.

Brandi Moore (M.S. 2016) Brandi used calcareous nannofossil assemblages to reconstruct surface water distributions and conditions during the Late Santonian and Early Campanian.
Shamar Chin (M.S. 2016)

Shamar examined the calcareous nannofossil quantitative biostratigraphy and paleoecology of the lower Cenomanian stage from the North Atlantic as a means to test the fidelity of existing zonation schemes. Shamar currently is pursuing her Ph.D. at the University of Nebraska (see above).

Zachary Kita (Ph.D. 2015)

Zachary examined the geochrological sequence of calcareous nannofossil events in the Coniacian through lower Campanian of the Western Interior Basin of North America in comparison to a newly generated high-resolution carbon isotope curve. While at UNL, he was a shipboard scientist (nannofossil paleontologist) on IODP Expedition 350 to the Izu-Bonin-Mariana Rear Arc. Some of his taxonomic work has been published in the Journal of Nannoplankton Research. His biostratigraphic work has been published in Cretaceous Research. After graduation, Zack joined BP in Houston as a biostratigrapher.

Matthew Corbett (Ph.D. 2013)

Matt examinied the nannofossil biostratigraphy of the Cenomanian-Turonian Eagle Ford Formation from outcrop exposures in western Texas and correlative units from the Western Interior Basin. His research on Oceanic Anoxic Event 2 is published in Palaeo3. His work on the quantitative biostrratigraphy is published in Marine Micropaleontology. His work on Western Interior nannofossil paleoecology is published in Palaeo3 and Stratigraphy. Our work on the Eprolithus-Lithastrinus transition is published in Micropaleontology. After gtraduation, Matt became a nannofossil micropaleontogist at BP in Houston.

Bobbi Brace (M.S. 2012)

Bobbi studied the nannofossil genus Biscutum during its mid- and Late Cretaceous diversification in the western central Atlantic, Gulf of Mexico, and the Western Interior Basin. Her research is published in Micropaleontology and in the Journal of Nannoplankton Research. Bobbi is currently pursuing a Ph.D. program at the University of Nebraska (see above).

Johnathon Kell (M.S. 2012)

Johnathon examined the relationship of orbitally-driven surface water variations and nannofossil paleocommunity structure in the middle Eocene from Leg 171. He also participated in the International Ocean Drilling Program (IODP) Leg 330 expedition to the Louisville Seamounts of the South Pacific. The results of this work is published in Proceedings of the Integrated Ocean Drilling Program. After graduation, John worked as a nannofossil paleontologist with Fugro-Robertson in northern Wales.

Andy Bowman (Ph.D. 2011)

Andy studied the quantitative biostratigraphy of the nannofossils from the Paleocene/Eocene transition to the middle Eocene of the Gulf of Mexico and western North Atlantic. In addition, he used quantitative methods to study the paleoecology of these Paleogene assemblages. He also used quantitative biostratigraphic methods to propose a new zonation for the Miocene of the Gulf of Mexico (published in SEPM Special Publication No. 93). He currently is employed at Statoil as a Nannofossil Biostratigrapher.

Jamie Shamrock (Ph.D. 2010)

Jamie used nannofossils to construct a biostratigraphic and paleoecologic framework for the Eocene deep water deposits off the northwestern Australian margin, in cooperation with Exxonmobil. Her research results on the Sphenolithus lineage are published in the Journal of Nannoplankton Research. Her results on biostratigraphy, biogeochronology, and paleocommunity structure are published in Stratigraphy. She is currently employed at ExxonMobil as a Nannofossil Micropaleontologist.

John Sarao (M.S. 2009)

John used carbonate content and nannofossil assemblage changes to characterize the invasion of oceanic surface waters into the Western Interior Seaway during the early to late Maastrichtian using outcrop samples from the Mobridge Member (Pierre Shale). After graduation he joined Paleodata, Inc. as a Nannofossil Micropaleontologist.

Jamie Shamrock (M.S. 2008)

Jamie analyzed the evolution of the genus Eiffellithus, an important biostratigraphic and paleoecologic indicator in the Upper Cretaceous. She differentiated several new taxa and documented a pattern of iterative evolution. Her research results are published in Cretaceous Research. She presented the results of her research at the 2008 AAPG Convention, where she was awarded Honorable Mention in the SEPM Excellence of Poster Presentation. After graduation she entered the Ph.D. program at the University of Nebraska (see above).

Stacie A. Blair (M.S. 2006)

Stacie used calcareous nannofossils to construct a high-resolution biostratigraphy for the Coniacian/Santonian stage boundary in the Western Interior Basin. Her research results are published in Cretaceous Research. After graduation she entered the Ph.D. program at Florida State University.

Ryan Weber (M.S. 2006)

Ryan used nannofossils as evidence for an impact-induced tsunami in the Late Cretaceous Western Interior Seaway from the Crow Creek Member (Pierre Shale). His work is published in Geology. After graduation he joined Paleodata, Inc. as a Nannofossil Micropaleontologist.

Todd Boesiger (M.S. 2005) Todd examined the calcareous nannoplankton response to regression of the Campanian Niobrara Sea. After graduation he joined BP America, Inc. as a Nannofossil Paleontologist.
Emily Browning (M.S. 2005) Emily’s research demonstrated elevated primary productivity of calcareous nannoplankton associated with Ocean Anoxic Event 1b (Aptian-Albian) using core material from Ocean Drilling Program Leg 171b. Her research results are published in Paleoceanography. After graduation she entered the Ph.D. program at the University of Massachusetts-Amherst.


Recent Publications

Huber, B.T., M. R. Petrizzo, D. K. Watkins, S. J. Haynes, and K. G. MacLeod, 2017, Correlation of Turonian continental margin and deep-sea sequences in the subtropical Indian Ocean sediments by integrated planktonic foraminiferal and calcareous nannofossil biostratigraphy, Newsletters on Stratigraphy, 50, 141-185.
Haynes, S.J.,  K.G. MacLeod, B.T. Huber, S. Warny, A.J. Kaufman, R.D. Pancost, A.J. Berrocoso, M.R. Petrizzo, D.K. Watkins, I. Zhelezinskaia, 2017, Southeastern Tanzania depositional environments, marine and terrestrial links, and exceptional microfossil preservation in the warm Turonian. Geological Society of America Bulletin. doi: 10.1130/B31432.1.
Kita, Z.A., Watkins, D.K., Sageman, B.B., 2016, High-resolution calcareous nannofossil biostratigraphy of the Santonian/Campanian Stage boundary, Western Interior Basin, USA, Cretaceous Research, doi: 10.1016/j.cretres.2016.08.015.
Kita, Z.A., D.K. Watkins, and J.A. Bergen, 2016, A new calcareous nannofossil species of the genus Helicolithus from the Santonian and its biostratigraphic significance in the Cretaceous Western Interior Seaway, Journal of Nannoplankton Research, 36, 77-82.
Brace, B.J., and D.K. Watkins, 2015, Global abundance decline in the productivity indicator Biscutum during the Cretaceous. Journal of Nannoplankton Research, 30, 129-140.
Ando, A., B.T. Huber, K.G. MacLeod, and D.K. Watkins, 2015, Early Cenomanian “hot greenhouse” revealed by oxygen isotope record of exceptionally well-preserved foraminifera from Tanzania. Paleoceanography, 30, 1556-1572.  doi:10.1002/2015PA002854
Brace, B.J. and D.K. Watkins, 2014, Evolution of the Calcareous Nannofossil Genus Biscutum in the middle to Upper Cretaceous North American mid-latitudes, Micropaleontology, 60, 445-463.
Corbett, M.J., and D.K. Watkins, 2014, Cenomanian through basal Coniacian Calcareous Nannofossil biostratigraphy of the Mancos Shale reference section, Mesa Verde National Park, CO, Stratigraphy, 11, 97-108.
Kell, J.P. and David K. Watkins, 2014, Data report: calcareous nannofossil biostratigraphy of Expedition 330, Louisville Seamount Trail, Sites U1372–U1377, Koppers, A.A.P., Yamazaki, T., Geldmacher, J., and the Expedition 330 Scientists, Proceedings of the Integrated Ocean Drilling Program, Volume 330. doi:10.2204/iodp.proc.330.201.2014
Lowery, C.M., M.J. Corbett, R.M. Leckie, D.K.Watkins, T.S. Staerker, A.D. Donovan, A. Miceli-Romero, and A. Pramudito, 2014, Foraminiferal and Nannofossil paleoecology and paleoceanography of the Cenomanian-Turonian Eagle Ford Shale of southern Texas, Palaeogeography,  Palaeoclimatology, Palaeoecology. doi.org/10.1016/j.palaeo.2014.07.025
Corbett, M.J., D.K. Watkins, and J.J. Pospichal, 2014, Quantitative Analysis of Calcareous Nannofossil Bioevents of the Late Cretaceous (Late Cenomanian-Coniacian) Western Interior Seaway and their Reliability in Established Zonation Schemes, Marine Micropaleontology, doi:10.1016/j.marmicro.2014.04.002.
Corbett, M.J., and D.K. Watkins, 2014, Transitional forms in the Eprolithus-Lithastrinus lineage: a taxonomic revision of Turonian through Santonian species, Micropaleontology, 60.
Corbett, Matthew J., Watkins, David K., 2013, Calcareous Nannofossil Paleoecology of the mid-Cretaceous Western Interior Seaway and Evidence of Oligotrophic Surface Waters during OAE2, Palaeogeography, Palaeoclimatology, Palaeoecology(2013), doi: 10.1016/j.palaeo.2013.10.007
Self-Trail, J.M., D.S. Powars,  D.K. Watkins, G. Wandless, 2012, Calcareous Nannofossil Assemblage Changes Across the Paleocene-Eocene Thermal Maximum: Evidence from a Shelf Setting, Marine Micropaleontology, 92–93, 61–80.
Shamrock, J.L., D.K. Watkins, and K.W. Johnston, Eocene bio-geochronology of ODP Leg 122 Hole 762C, Exmouth Plateau (northwest Australian Shelf), Stratigraphy 9, 55-76.
Shamrock,. J.L., and D.K. Watkins, 2012, Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Exmouth Plateau, Eastern Indian Ocean (ODP Hole 762C), Stratigraphy, 9, 1-54.
Blair, S.A,, and D.K. Watkins, 2009, High-resolution calcareous nannofossil biostratigraphy for the Coniacian/Santonian Stage boundary, Western Interior Basin, Cretaceous Research, 30, 367-384, doi:10.1016/j.cretres.2008.07.016.
Shamrock, J.L., and D.K. Watkins, 2009, Evolution of the Cretaceous calcareous nannofossil genus Eiffellithus and its biostratigraphic significance, Cretaceous Research, 30, 1083-1102, doi:10.1016/j.cretres.2009.03.009
Browning, E. L., and D. K. Watkins (2008), Elevated primary productivity of calcareous nannoplankton associated with ocean anoxic event 1b during the Aptian/Albian transition (Early Cretaceous), Paleoceanography, 23, PA2213, doi:10.1029/2007PA001413.
Weber, R.D., and D.K. Watkins, 2007, Evidence from the Crow Creek Member (Pierre Shale) for an impact-induced resuspension event in the Late Cretaceous Western Interior Seaway, Geology, 35, 119-1122.
Watkins, D.K., 2007, Quantitative analysis of the calcareous nannofossil assemblages from CIROS-1, Victoria Land Basin, Antarctica, Journal of Nannoplankton Research, 29, 130-137.
Watkins, D.K., M.J. Cooper, and P.A. Wilson, 2005, Calcareous nannoplankton response to late Albian Oceanic Anoxic Event 1d in the Western North Atlantic, Paleoceanography, 20, 14 p., doi:10.1029/2004PA001097.
Watkins, David K.and J.M. Self-Trail, 2005, Calcareous nannofossil evidence for the existence of the Gulf Stream during the late Maastrichtian, Paleoceanography, 20, 9 p. doi 10.1029/2004PA001121.
Holmes, M.A., D.K. Watkins, and R.D. Norris, 2004, Paleocene cyclic sedimentation in the western North Atlantic, ODP Site 1051, Marine Geology, 209, 31-43.
Watkins, D.K., and J.A. Bergen, 2003, Late Albian adaptive radiation in the calcareous nannofossil genus Eiffellithus, Micropaleontology, 49, 231-252.


Graduate Courses

Marine Geology and Paleoceanography (3 cr.) - Geology of the oceanic realm, formation of oceanic crust, circulation, geochemistry, pelagic sediments and their diagenesis, correlation and ocean history.
Mesozoic Calcareous Nannofossil Paleontology (4 cr) – Biostratigraphy, paleoecology, and paleobiogeography of Mesozoic calcareous nannofossils.
Cenozoic Calcareous Microfossil Paleontology (4 cr.) – Biostratigraphy, paleoecology, and paleobiogeography of Cenozoic calcareous nannofossils.
Quantitative Methods in Paleontology (3 cr.) - Numerical and statistical analysis of paleontological data including biometry, synecology, and quantitative biostratigraphy.