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Caroline A.E. Strömberg, Ph.D.

Curator of Paleobotany


(206) 543-0495

Paleobotany and Paleoecology Laboratory


2007 Postdoctoral Fellow, National Museum of Natural History, Smithsonian Institution, Washington, DC

2004-2006 Postdoctoral Fellow, Swedish Museum of Natural History, Stockholm, Sweden

2003 Ph.D., Department of Integrative Biology, University of California, Berkeley

1997 B.A., M.Sc., Department of Geology, Lund University, Sweden

Dr Stromberg

grass phytolith


Cenozoic evolution of grasses and grazers

The evolution of grassland ecosystems was one of the most profound ecological changes of the past 65 million years, but many questions remain as to when it occurred and what triggered it. A traditional, yet untested assumption is that many animals (e.g., horses, dung beetles) evolved in lockstep with the spread of grass-dominated vegetation. I investigate these questions by using a novel source of paleobotanical data, plant silica (phytoliths), integrated with information from, for example, sedimentology, modern ecology, plant anatomy, and vertebrate paleontology. This work entails paleontological and geologic fieldwork in areas such as the North American continental interior, Argentina, Turkey, Spain, and China, laboratory work, as well as systematic, statistical, and phylogenetic analysis. Many of these projects involve international collaborators including from Duke University, Geologic Survey of Turkey, Utrecht University, Netherlands, University of Birmingham, UK, University of Helsinki, Finland, and National Museum of Natural Science, Madrid, Spain. 

Origin, early diversification, and biogeography of the grass clade

Grasses evolved in the Late Cretaceous, in parallel with the break-up of Gondwana. It is less clear how this species-rich and ecologically important group reached its current global distribution and what the earliest interactions with herbivores were. My research on grass phytoliths preserved in coprolites from the Late Cretaceous of India with colleagues at the Birbal Sahni Institute of Palaeobotany, Lucknow and the Panjab University, Chandigarh attempts to address these questions.

Ecology of Late Cretaceous angiosperms

Angiosperms had reached high taxonomic diversity by the Late Cretaceous, but were still marginal in terms of relative abundance in mid-high latitude vegetation in North America. Together with Scott Wing (National Museum of Natural History, Smithsonian Institution) and colleagues, I investigate vegetation structure and the ecological role(s) that angiosperms played in the Late Cretaceous, using an exceptionally preserved fossil flora at the Big Cedar Ridge, central Wyoming.



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

Strömberg, C.A.E., 2009. Methodological concerns for analysis of phytolith assemblages: Does count size matter? Quaternary International 93: 124-140.

Strömberg, C.A.E., 2009. Reply to comment on the paper in Quaternary International: "Methodological concerns for analysis of phytolith assemblages: Does count size matter?" (A. Alexandre and L. Bremond) Quaternary International 93: 143-145.

Strömberg, C.A.E., Werdelin, L., Friis, E. M., and Saraç, G, in press. The spread of grass-dominated habitats in Turkey and surrounding areas during the Cenozoic: phytolith evidence. Palaeogeography, Palaeoclimatology, Palaeoecology.

Strömberg, C.A.E. and Zhang, Z., in press. Neogene climatic and biotic changes in Eastern Eurasia: Preface. Vertebrata PalAsiatica.

Strömberg, C.A.E., Friis, E.M., Liang, M.-M., Werdelin, L., and Zhang, Y-l., in press. Palaeoecology of an Early-Middle Miocene lake in China: preliminary interpretations based on phytoliths from the Shanwang Basin. Vertebrata PalAsiatica.

Strömberg, C.A.E., in press. Can slide preparation methods cause size biases in phytolith assemblages?: Results from a preliminary study. In Madella, M., Zurro, D. and Jones, M. K. (eds.): Places, People and Plants: Using Phytoliths in Archaeology and Palaeoecology. Oxbow Books.

Strömberg, C.A.E., 2006. The evolution of hypsodonty in equids: Testing a hypothesis of adaptation. Paleobiology32(2): 236-258.

Prasad, V., Strömberg, C.A.E.*, Alimohammadian, H., Sahni, A., 2005. Dinosaur coprolites and the early evolution of grasses and grazers. Science 310: 1177-1180.(*Applicant was corresponding author and contributed to the paper by identifying and describing the fossil phytoliths and the modern reference material, placing the fossils taxonomically, and writing a substantial part of the paper.)

Strömberg, C.A.E., 2005. Decoupled taxonomic radiation and ecological expansion of open-habitat grasses in the Cenozoic of North America. Proceedings of the National Academy of Sciences U.S.A.102(34): 11980-11984.

Strömberg, C.A.E., 2004. Using phytolith assemblages to reconstruct the origin and spread of grass-dominated habitats in the Great Plains of North America during the late Eocene to early Miocene. Palaeogeography, Palaeoclimatology, Palaeoecology 207(3-4): 239-275.

Strömberg, C.A.E., and Feranec, R.S., 2004. The evolution of grass-dominated ecosystems during the late Cenozoic: Preface. Palaeogeography, Palaeoclimatology, Palaeoecology 207(3-4): 199-201.

Strömberg, C.A.E., 2003. The origin and spread of grass-dominated ecosystems during the Tertiary of North America and how it relates to the evolution of hypsodonty in equids. Ph.D. thesis, Department of Integrative Biology, University of California at Berkeley. 779 pp.

Strömberg, C.A.E. 2002. The origin and spread of grass-dominated ecosystems in the Late Tertiary of North America: Preliminary results concerning the evolution of hypsodonty. Palaeogeography Palaeoclimatology Palaeoecology 177: 59-75.

Strömberg, C.A.E., 1997. The conodont genus Ctenognathodus in the Silurian of Gotland, Sweden. Examensarbete i Geologi vid Lunds Universitet vol. 85. Master's Thesis, Lund University, Sweden. 56 pp.