Faculty Support: Melinda Peterson

The main goal of my research is to better understand the substantial extinct biodiversity of invertebrate metazoans that first appeared and rapidly diversified during the Paleozoic Era, the period of time comprising between 541 and 251 million years ago. Most of our current work focuses on the study of several Lower Paleozoic sites of exceptional preservation around the world. These remarkable fossiliferous deposits contain critical information on the morphology and organization of soft-bodied organisms, including details of the internal anatomy, which are otherwise dramatically underrepresented in the rock record. Our group has a strong interest in the origin and subsequent radiation of Ecdysozoa (moulting animals) during the Cambrian Explosion and the Great Ordovician Biodiversification Event, with emphasis on the morphology, phylogeny and development of extinct panarthropods – whose extant representatives include euarthropods, tardigrades and onychophorans. To this end, we combine traditional paleontological approaches with cutting edge techniques to obtain new morphological information from the fossils, test macroevolutionary hypotheses through deep time, and ultimately clarify the origin of the major animal groups that have shaped the biosphere for more than 500 million years.

Recent Publications

S.R. Losso and J. Ortega-Hernández. 2022. Claspers in the mid-Cambrian Olenoides serratus indicate horseshoe crab-like mating in trilobites. Geology, 50, Pp. 897-901.

J. Ortega-Hernández, R. Lerosey-Aubril, S.R. Losso, and J. C. Weaver. 2022. Neuroanatomy in a middle Cambrian mollisoniid and the ancestral nervous system organization of chelicerates. Nature Communications, 13, 410.

R. Lerosey-Aubril and J. Ortega-Hernández. 2022. A new lobopodian from the middle Cambrian of Utah: did swimming body flaps convergently evolve in stem-group arthropods? Papers in Palaeontology, 8, Pp. e1450.

R.D.C. Bicknell, J. Ortega-Hernández, G.D. Edgecombe, R.R. Gaines, and J.R. Paterson. 2021. Central nervous system of a 310-million-year-old horseshoe crab: expanding the taphonomic window for nervous system preservation.”Geology, 49, 11, Pp. 1381-1385.

L.A. Parry, R. Lerosey-Aubril, J. C. Weaver, and J. Ortega-Hernández. 2021. Cambrian comb jellies from Utah illuminate the early evolution of nervous and sensory systems in ctenophores. iScience, 24, Pp. 102943.

M.A. . Mapalo, N. Robin, B. E. Boudinot, J. Ortega-Hernández, and P. A. Barden. 2021. A tardigrade in Dominican amber. Proceedings of the Royal Society B , 288, Pp. 20211760

Y. Liu, J. Ortega-Hernández, D. Zhai, and X. G. Hou. 2020. A reduced labrum in a Cambrian great-appendage euarthropod. Current Biology, 30, Pp. 3057-3061.

Ortega–Hernández, J. 2019.Exceptionally preserved Cambrian fossils in the genomic era. In Martín-Durán, J.M., and Vellutini, B. eds. “Old Questions and Young Approaches to Animal Evolution”. Fascinating Life Sciences. Springer, Cham. pp. 39-54.

Zhai, D., Ortega–Hernández, J., Wolfe, J. M., Hou, X.G., Cao, C.J., and Liu, Y. 2019. Three-dimensionally preserved appendages in an early Cambrian stem-group pancrustacean. Current Biology 29 (1): 171-177.