Optics and phylogeny: is there an insight? The evolution of superposition eyes in the Decapoda (Crustacea)

This paper addresses the use of eye structure and optics in the construction of crustacean phylogenies and presents an hypothesis for the evolution of superposition eyes in the Decapoda, based on the distribution of eye types in extant decapod families. It is suggested that reflecting superposition optics are symplesiomorphic for the Decapoda, having evolved only once, probably in the Devonian. Subsequent loss of reflecting superposition optics has occurred following the adoption of a new habitat (e.g. Aristeidae, Aeglidae) or by progenetic paedomorphosis (Paguroidea, Eubrachyura).