Discovery of some 400 million year-old sensory structures in the compound eyes of trilobites
Brigitte Schoenemann & Euan N. K. Clarkson
Affiliations Contributions Corresponding author
Scientific Reports 3, Article number: 1429 doi:10.1038/srep01429
Received 11 December 2012 Accepted 26 February 2013 Published 14 March 2013
Fossilised arthropod compound eyes have frequently been described. Among the oldest known are those from the lower Cambrian of the Chengjiang Lagerstätte (China, c 525 Ma). All these compound eyes, though often excellently preserved, however, represent just the outer shells, because soft tissues, or even individual cells, usually do not fossilise. Using modern techniques, including μct-scanning and synchrotron radiation analysis we present the discovery of the sensory cell system of compound eyes, belonging to trilobites around 400 million years old, which allows their description and analysis. They are interpreted as forming part of an apposition-like ommatidium, which is a basic functional type of compound eye present in arthropods of today. Considered in greater detail, it is similar to the compound eye of the horseshoe crab Limulus, generally regarded as a ‘living fossil’, which probably retained this ancient basal system successfully until today.
Subject terms: Palaeontology Neurophysiology Zoology Cellular imaging