Faculty

My research centers on understanding the paleobiology of extinct echinoderms (starfish and their allies). My research tends to be phylogenetically oriented and echinoderms lend themselves to a phylogenetic approach because their intricate morphology, coupled with a high degree of morphological disparity, allow for the coding of robust datasets for phylogenetic analysis.  My work is focuses primarily on the Cambrian and Ordovician echinoderm radiations from a global perspective and understanding the post Devonian divergence of brittle stars.  I use specimens housed in museum collections, supplemented by an active field program to collect new material at critical intervals.

At present I am focusing on four fundamental questions:

• What is the nature of the Cambrian-Ordovician explosive radiation of echinoderm body plans? 
• How can phylogeny and development be used to answer paleontological questions? 
• What is the underlying homology of skeletal elements in echinoderms and how can it be used to increase the fidelity of character data used to infer phylogeny?
• How does collecting bias influence our understanding of the Paleozoic brittle star fossil record?

Ph.D. (1996) University of Texas at Austin (Dr. James Sprinkle, advisor)

M.A. (1991) University of Texas at Austin (Dr. James Sprinkle, advisor)

B.S. (1989) Arizona State University, magna cum laude (Dr. Robert Lundin, advisor)

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Recent publications

• Sumrall, C.D. 2017. New insights concerning homology of the oral area and ambulacral system in echinoderms. In, S. Zamora (ed.) Progress in Echinoderm Paleontology, Special issue of Journal of Paleontology. 91 (4), 604-617.
• Sheffield, S.A. and C.D. Sumrall. 2017. Generic revision of the Holocystites Fauna of North America (Diploporita: Echinodermata) based on universal elemental homology. In, S. Zamora (ed.) Progress in Echinoderm Paleontology, Special issue of Journal of Paleontology. 91 (4), 755-766.
• Bauer, J.E., C.D. Sumrall, and J.A. Waters. 2017. Hydrospire morphology and its implications for blastoid phylogenetic inference. In, S. Zamora (ed.) Progress in Echinoderm Paleontology, Special issue of Journal of Paleontology. 91 (4), 847-857.
• Waters, J.A., L.E. White, C.D. Sumrall, and B.K. Nguyen. 2017. A new model of respiration in blastoid (Echinodermata) hydrospires based CFD simulations of virtual 3D models. In, S. Zamora (ed.) Progress in Echinoderm Paleontology, Special issue of Journal of Paleontology. 91 (4), 662-671.
• Sheffield, S.A., W.I. Ausich and C.D. Sumrall. 2018. Late Ordovician (Hirnantian) diploporitan fauna of Anticosti Island, Quebec, Canada: implications for evolutionary and biogeographic patterns. Canadian Journal of Earth Sciences. 55(1), 1-7.
• Zamora, S. and C.D. Sumrall. 2018. First report of coronates (Echinodermata) from Africa. In Hunter, A. (ed.) The Upper Ordovician Echinoderm Fauna from the Anti-Atlas Mountains of Morocco, Special Papers in Palaeontology. V. 485.
• Sumrall, C.D. and S. Zamora. 2018. New data on edrioasteroids from the Upper Ordovician of the Anti-Atlas (Morocco). In Hunter, A. (ed.) The Upper Ordovician Echinoderm Fauna from the Anti-Atlas Mountains of Morocco, Special Papers in Palaeontology. V. 485.
• Sheffield, S.L and C.D. Sumrall. 2019. A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa: Echinodermata) and its bearing on the evolution of early crinoids. Palaeontology. 62(1), 163-173.
• Shroat-Lewis, R.A., E. Greenwood and C.D. Sumrall. 2019. Paleoecologic analysis of edrioasteroid (Echinodermata) encrusted slabs from the Chesterian (Upper Mississippian) Kinkaid Limestone of southern Illinois, PAILOS. 34(3), 146-158.
• Bauer, J.E., J.A. Waters and C.D. Sumrall. 2019. Reevaluation of Macurdablastus with implications for the origins of Eublastoidea. Palaeontology. 62(6), 1003-1013.
• Zamora, S. and C.D. Sumrall. 2019. Hexedriocystis, an aberrant eocrinoid convergent with edrioasteroids from the Upper Ordovician of Morocco.  In Hunter, A. (ed.) The Upper Ordovician Echinoderm Fauna from the Anti-Atlas Mountains of Morocco, Special Papers in Palaeontology. V. 485.
• Sheffield, S.L. and C.D. Sumrall. 2019. The phylogeny of the Diploporita: a polyphyletic assemblage of blastozoan echinoderms. Journal of Paleontology, 93(4):740-752.
• Carerra, M. and C.D. Sumrall. 2019. Ordovician Sponges from the Lenoir Limestone, Tennessee: New evidence for a differential sponge distribution along the Laurentian Margin, Journal of Paleontology. 94(1), 34-44.
• Paton, T., R. Freeman, B. Datillo, C.E. Brett, and C.D. Sumrall. 2019. Taphonomic feedback of an edrioasteroid-encrusted coral graveyard from the upper Ordovician (Cincinnatian, Richmondian) of central Kentucky. Palaeogeography, Palaeoclimatology, Palaeoecology. 537(2020), 109447.
• Zamora, S., D. Wright, R. Mooi, B. Lefebvre, T.E. Guensburg, P. Gorzelak, B. David, L. Cole, C.D. Sumrall, Aaron Hunter, J. Sprinkle, J. Thompson, T. Ewin, O. Fatka, E. Nardin, M. Reich, M. Nohejlová, and I.A. Rahman.. 2020. Re-evaluating the phylogenetic position of the enigmatic early Cambrian deuterostome Yanjiahella. Nature Communications. 11(1286).
• Deline, B., J.R. Thompson, N.S. Smith, S. Zamora, I.A. Rahman, S.L. Sheffield, W.I. Ausich, T.W. Kammer, and C.D. Sumrall. 2020. Evolution and development at the origin of a phylum. Current biology. 30(9), 1672-1679.
• Zamora, S., J. Sprinkle, and C.D. Sumrall. 2020. A revaluation of Rhipidocystidae based on a new flattened eocrinoid (Blastozoa, Echinodermata) from the Upper Ordovician of Maryland (USA). Acta Paleontologica Polonica. 65(3), 455-465.
• Brochu, C.A. and C.D. Sumrall. 2020. Modern cryptic species and crocodylian diversity in the fossil record. Zoological Journal of the Linnean Society. 198(2), 700-711.
  Sumrall, C.D. and D. Phelps. 2020. Spiracarneyella a new carneyellid edrioasteroid from the Upper Ordovician (Katian) of Kentucky and Ohio and comments on carneyellid heterochrony. Journal of Paleontology.
• Sumrall, C.D. 2020. Pan-Echinodermata. p. 641-644, Echinodermata. p. 645-648, Edrioasterida. p. 649-650, Isorophida. p. 651-652,  Isorophina. p. 653-654, Agelacrinitidae. p. 655-656, Lepidodiscina. p. 657-658, and Discocystinae. p. 659-660. In K. de Queiroz, J. Gauthier, and P. Cantino (eds.) Phylonyms: A Companion Volume to the PhyloCode. Taylor & Francis Group, London. (This peer-reviewed edited volume is the official document that replaces the 250 year-old Linnaean Classification of life with the PhyloCode tree based classification.)