Mark Webster
Mark Webster
Assistant Professor of Paleobiology
Phone: (773) 702-4071
Email: mwebster@geosci.uchicago.edu
Office #: 233
Research interests:
My research focuses on the understanding of modes and constraints in morphological evolution at the microevolutionary scale, and how these affect parameters of clade diversification such as evolutionary rate, evolutionary trends, and morphospace occupation at a macroevolutionary scale. My primary interest lies in the Trilobita, a group offering outstanding opportunities for studying the details of morphological evolution in a tightly constrained phylogenetic, environmental, temporal, and geological framework over short and long time intervals. The work involves detailed comparative analysis of the morphological variation, ontogenetic development, functional morphology, and systematics of trilobite species, employing and developing cutting-edge methods in morphometrics and cladistics. The significance of my work lies in the detail in which it is conducted, which allows unprecedented insight into evolutionary mechanisms and constraints - the implications of which extend well beyond trilobite evolution. High-resolution (sub-meter scale) stratigraphic collecting permits patterns of morphological evolution to be framed within paleoenvironmental and sequence stratigraphic context, thus producing an integrative approach to stratigraphic paleobiology. The research forms important contributions to Cambrian paleontology and biostratigraphy, and has far-reaching implications for the broader fields of paleobiology, evolutionary developmental biology, and the integration of stratigraphy and morphometrics with cladistics.
Publications:
Webster, M. In Review. Systematic revision of the Cambrian trilobite Bathynotus Hall, 1860, with documentation of new occurrences in western Laurentia and implications for intercontinental biostratigraphic correlation. Submitted to Memoirs of the Association of Australasian Paleontologists.
Hopkins, M. J., and M. Webster. In Press. Ontogeny and geographic variation of a new species of the corynexochine trilobite Zacanthopsis (Dyeran, Cambrian). Journal of Paleontology.
Webster, M. 2009. Ontogeny, systematics, and evolution of the effaced early Cambrian trilobites Peachella Walcott, 1910 and Eopeachella new genus (Olenelloidea). Journal of Paleontology 83 (2): 197-218. [PDF LINK]
Webster, M., and M. L. Zeldtich. 2008. Integration and regulation of developmental systems in trilobites. Pp. 427-433 in Rábano, I., Gozalo, R., and García-Bellido, D (eds.), Advances In Trilobite Research. Cuadernos del Museo Geominero 9. Instituto Geológico y Minero de España, Madrid. [PDF LINK]
Hopkins, M. J., and M. Webster. 2008. Morphological and ontogenetic change in the "Early" Cambrian trilobite Zacanthopsis during an interval of environmental change. Pp. 185-187 in Rábano, I., Gozalo, R., and García-Bellido, D (eds.), Advances In Trilobite Research. Cuadernos del Museo Geominero 9. Instituto Geológico y Minero de España, Madrid. [PDF LINK]
Webster, M., R. R. Gaines, and N. C. Hughes. 2008. Microstratigraphy, trilobite biostratinomy, and depositional environment of the "Lower Cambrian" Ruin Wash Lagerstätte, Pioche Formation, Nevada. Palaeogeography, Palaeoclimatology, Palaeoecology 264: 100-122.
Webster, M. 2007. Paranephrolenellus, a new genus of Early Cambrian olenelloid trilobite. Memoirs of the Association of Australasian Paleontologists 34: 31-59. [PDF LINK]
Webster, M. 2007. Ontogeny and evolution of the Early Cambrian trilobite genus Nephrolenellus (Olenelloidea). Journal of Paleontology 81 (6): 1168-1193. [PDF LINK]
Webster, M. 2007. A Cambrian peak in morphological variation within trilobite species. Science 317: 499-502. [PDF LINK]
Webster, M., and M. L. Zelditch. 2005. Evolutionary modifications of ontogeny: heterochrony and beyond. Paleobiology 31 (3): 354-372.
Fusco, G., N. C. Hughes, M. Webster, and A. Minelli. 2004. Exploring developmental modes in a fossil arthropod: growth and trunk segmentation of the trilobite Aulacopleura konincki. American Naturalist 163 (2): 167-183.
Webster, M., P. M. Sadler, M. A. Kooser, and E. Fowler. 2003. Combining stratigraphic sections and museum collections to increase biostratigraphic resolution: Application to Lower Cambrian trilobites from southern California. Pp. 95-128 in P. J. Harries (ed.), High-Resolution Approaches in Stratigraphic Paleontology. Topics in Geobiology, Volume 21. Kluwer Academic Publishers, Dordrecht.
Webster, M., H. D. Sheets, and N. C. Hughes. 2001. Allometric patterning in trilobite ontogeny: Testing for heterochrony in Nephrolenellus. Pp. 105-144 in M.L. Zelditch (ed.), Beyond Heterochrony: The Evolution of Development. John Wiley and Sons, New York.
Dunlop, J. and M. Webster. 1999. Fossil evidence, terrestrialization and arachnid phylogeny. Journal of Arachnology 27: 86-93.
Webster, M., and N. C. Hughes. 1999. Compaction-related deformation in Cambrian olenelloid trilobites and its implications for fossil morphometry. Journal of Paleontology 73: 355-371.
Bowden, A., M. Webster, and T. Mitcham. 1997. Salthill Quarry Geology Trail. Geologists' Association Guide No. 58. Geologists' Association, London. 30 pp.
Courses:
Undergraduate Courses
Geos 22400: Invertebrate Paleobiology and Evolution (with field trip).
Geos 28100: Field Course in Geology.
Graduate Courses
Geos 32700: Morphometrics.
Geos 32900: Species and the Fossil Record.
Education:
2003: University of California, Riverside (U.S.A.). Postdoctoral research position with P. M. Sadler (January to July).
1998-2002: University of California, Riverside (U.S.A.). Ph.D. Degree. Ontogeny and Phylogeny of Early Cambrian Olenelloid Trilobites, with Emphasis on the Late Dyeran Biceratopsidae. (Degree conferred March 2003)
1996-1998: University of California, Riverside (U.S.A.). M.S. Degree. Paleobiologic Aspects of Olenelloid Trilobites from the Uppermost Dyeran C-Shale Member of the Pioche Formation, Nevada. (August 1996 to August 1997 spent at the University of Cincinnati, Ohio).
1993-1996: University of Manchester (England). First Class B.Sc. Degree with Honors in Biology and Geology.
Employment:
2004-present: University of Chicago (U.S.A.). Assistant Professor of Paleobiology, Department of the Geophysical Sciences, and Committee on Evolutionary Biology (from July 2004).
2003-2004: University of California, Los Angeles (U.S.A.). Assistant Professor of Paleobiology, Department of Earth and Space Sciences.
