Phylogeny, evolution and development of Ecdysozoa

Ecdysozoans are by far the most successful animals to ever exist in terms of their diversity, abundance, and ecological impact. These organisms are well represented in Paleozoic deposits by virtue of their durable external cuticle, and thus are ideally suited for studying the early radiation of complex metazoans. Our work on ecdysozoan evolution focuses on the origin of its main constituent groups, such as the euarthropods, as informed by soft-bodied fossils from Cambrian and Ordovician Konservat-Lagerstätten. We employ developmental biology data from model organisms to accurately reconstruct the morphology and body patterning of problematic extinct taxa, and thus clarify their phylogenetic relationships with extant groups and broader evolutionary significance.


Evolution of head segmentation in total-group Euarthropoda - Ortega-Hernández et al. 2017, Arthropod Structure and Development 46: 354.

Representative publications:

- Fu, D., Ortega–Hernández, J., Daley, A.C., Zhang, X.-L., & Shu, D. 2018. Anamorphic development and extended parental care in 520 million-year-old stem-group euarthropod from China. BMC Evolutionary Biology 18: 147

- Yang. J., Ortega–Hernández, J., Legg, D. A., Tian, L., Hou, J.-B., & Zhang, X.-G. 2018. Early Cambrian fuxianhuiids from China reveal origin of the gnathobasic protopodite in euarthropods. Nature Communications 9: 470.

- Ortega–Hernández, J., Janssen, R. & Budd, G.E. 2017. Origin and evolution of the panarthropod head – a palaeobiological and developmental perspective. Arthropod Structure and Development 46: 354-379.

- Ortega–Hernández, J. 2016. Making sense of “lower” and “upper” stem-group Euarthropoda, with comments on the strict use of the name Arthropoda von Siebold, 1848. Biological Reviews 91: 255-573.

- Smith, M.R. & Ortega–Hernández, J. 2014. Hallucigenia’s onychophoran-like claws and the case for Tactopoda. Nature 514: 363-366.