Internal anatomy through deep time

In addition to non-biomineralized body fossils, Konservat-Lagerstätten also provide valuable information on the internal anatomy of extinct organisms. Although digestive tracts and gut glands are by far the most commonly fossilized internal organs, recent discoveries indicate that the central nervous system can also be preserved under truly exceptional circumstances in Cambrian Burgess Shale type deposits. Combined with the study of extant animals, these data offer unique insights into the ancestral organization of the non-exoskeletal morphology of panarthropods, and an improved understanding of the conditions necessary for the preservation of these labile tissues.

houghtonites_usnm

Exceptional preservation of the central nervous system in the soft-bodied euarthropod Mollisonia symmetrica from the middle Cambrian Burgess Shale in Canada. Illumination alternates between reflected light, polarized light, and polarized light under water in order to highlight internal organs. You can  download the Open Access publicaton HERE. Image by Javier Ortega–Hernández.

Representative publications:

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

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

- Bicknell, R.D., Ortega-Hernández, J., Edgecombe, G.D., Gaines, R.R. and Paterson, J.R., 2021. Central nervous system of a 310-my-old horseshoe crab: Expanding the taphonomic window for nervous system preservation. Geology 49: 1381-1385 .

- Ortega–Hernández, J., Lerosey-Aubril, R., & Pates, S. 2019. Proclivity of nervous system preservation in Cambrian Burgess Shale-type deposits. Proceedings of the Royal Society of London B 286: 20192370.

- Ortega–Hernández, J., Fu, D.J., Zhang, X.L. & Shu, D. 2018. Gut glands illuminate trunk segmentation in Cambrian fuxianhuiids. Current Biology 28: R146–R147.

- Yang. J., Ortega–Hernández, J., Butterfield, N.J., Liu, Y., Boyan, G., Tian, L., Hou, J.-B., & Zhang, X.-G. 2016. Fuxianhuiid ventral nerve cord and early nervous system evolution in Panarthropoda. Proceedings of the National Academy of Sciences 113: 2988-2993.

- Ortega–Hernández, J. & Budd, G.E. 2016. The nature of non-appendicular anterior paired projections in Palaeozoic total-group Euarthropoda. Arthropod Structure & Development 45: 185-199. 

- Ortega–Hernández, J. 2015. Homology of head sclerites in Burgess Shale euarthropods. Current Biology 25: 1625-1631.