Fossil echinoderms: biodiversity, systematics, & evolution

Echinoderms are represented by more than 7,000 species in today’s oceans and include familiar animals such as starfish, sea urchins, and sand dollars. Within the echinoderms, my taxonomic specialty is the Crinoidea (feather stars and sea lilies). Crinoids comprise an evolutionary lineage of reef-dwelling to deep water echinoderms represented by more than 8,000 fossil species that span ~480 million years of geologic history.

My research on crinoid systematics has resulted in a major phylogenetic revision of the Class Crinoidea (Wright et al., 2017), identified links between development in extant and fossil species to inform homology statements (Wright, 2015; Ausich et al., 2020), and led to the discovery new taxa, including 17 new species, 5 genera, and 1 family (e.g., Wright 2017a-b; Wright & Toom, 2017; Wright et al., 2019).

I have been actively involved in projects documenting new echinoderm species and occurrences from exceptionally well-preserved faunas from around the world, including the Ordovician Brechin Lagerstätte of Ontario, the oldest Paleozoic crinoids of the Baltic paleocontinent (Wright & Toom, 2017), and a re-evaluation of the oldest putative echinoderm from the early Cambrian of China and its implications for deuterostome evolution (Zamora et al., 2020). My current focus is on crinoid origins (both total-group and crown group) and the construction of supertrees for Ordovician-early Silurian species.

Representative publications

Zamora, S, Wright, D.F, Mooi R., Lefebvre, B, Guensburg, T.E., Gorzelak, P., David, B., Cole, S.R., Sumrall, C.D., Hunter, A., Sprinkle, J., Thompson, J.R., Ewin, T., Fatka, O., Nardin, E., Reich, M., Nohejlová, M., and Rahman, I.A., 2020, Re-evaluating the phylogenetic position of the enigmatic early Cambrian deuterostome Yanjiahella. Nature Communications, 11, Article number: 1286 Online.

Ausich, W.I., Wright, D.F., Cole, S.R., and Sevastopulo, G.D. , 2020, Homology of posterior interray plates in crinoids: a review and new perspectives from phylogenetics, the fossil record, and development. Palaeontology. doi:10.1111/pala.12475. Online

Wright, D.F., Cole, S.R., and Ausich, W.I., 2020 ,Biodiversity, systematics, and new taxa of cladid crinoids from the Upper Ordovician (Katian) Brechin  Lagerstätte. Journal of Paleontology, 94: 334-357. Online

Cole, S.R., Wright, D.F., and Ausich, W.I., 2019, Phylogenetic community paleoecology of one of the earliest complex crinoid faunas (Brechin Lagerstätte, Ordovician). Palaeogeography, Palaeoclimatology, Palaeoecology, 521:82-98.

Ausich, W.I., Wright, D.F., Cole, S.R., and Koniecki, J., 2018, Disparid and hybocrinid crinoids (Echinodermata) from the Upper Ordovician (lower Katian) Brechin Lagerstätte of Ontario. Journal of Paleontology, 92: 850-871.

Cole, S.R., Ausich, W.I., Wright, D.F., and Koniecki, J., 2018, An echinoderm Lagerstätte from the Upper Ordovician (Katian), Ontario: taxonomic re-evaluation and description of new dicyclic camerate crinoids. Journal of Paleontology, 92: 488-505.

Wright, D.F. and Toom, U. 2017, New crinoids from the Baltic region (Estonia): fossil tip-dating phylogenetics constrains the origin and Ordovician–Silurian diversification of the Flexibilia (Echinodermata). Palaeontology, 60: 893-910.

Wright, D.F., W.I. Ausich, S.R. Cole, M.E. Peter, and E.C. Rhenberg. 2017, Phylogenetic taxonomy and classification of the Crinoidea (Echinodermata). Journal of Paleontology, 91: 829-846.

Wright, D.F. 2017, Bayesian estimation of fossil phylogenies and the evolution of early to middle Paleozoic crinoids (Echinodermata). Journal of Paleontology, 91: 799-814.

Wright, D.F. 2017, Fossils, homology, and “Phylogenetic Paleo-ontogeny”: a reassessment of primary posterior plate homologies in fossil and living crinoids with insight from developmental biology. Paleobiology, 41:570-591.

Ausich, W.I., T.W. Kammer, E.C.  Rhenberg, and D.F. Wright. 2015, Early phylogeny of crinoids within the Pelmatozoan clade. Palaeontology, 58, 937-952.

Wright, D.F. and W.I. Ausich. 2015, From the stem to the crown: phylogeny and diversification of pan-cladid crinoids. Pp. 199-202 in Progress in Echinoderm Palaeobiology. S. Zamora and I. Rábano (eds.), Cuadernos del museo Geominero, 19, Instituto Geológico y Minero de España, 292 pp.

Ausich, W.I., T.W. Kammer, D.F. Wright, S.R. Cole, M.E. Peter, and E.C. Rhenberg. 2015, Toward a phylogenetic classification of the Crinoidea (Echinodermata). Pp. 29-32 in Progress in Echinoderm Palaeobiology. S. Zamora and I. Rábano (eds.), Cuadernos del museo Geominero, 19, Instituto Geológico y Minero de España, 292 pp.