Editing Trilobite (section)

===Prosopon (surface sculpture)===
[[File:Koneprusia brutoni.jpg|thumb|''Koneprusia brutoni'', an example of a species with elaborate spines from the [[Devonian]] [[Hamar Laghdad Formation]], [[Alnif]], [[Morocco]]|left]]
Trilobite exoskeletons show a variety of small-scale structures collectively called prosopon. Prosopon does not include large scale extensions of the cuticle (e.g. hollow pleural spines) but to finer scale features, such as ribbing, domes, pustules, pitting, ridging and perforations. The exact purpose of the prosopon is not resolved but suggestions include structural strengthening, sensory pits or hairs, preventing predator attacks and maintaining aeration while enrolled.<ref name=Whittington97a /> In one example, alimentary ridge networks (easily visible in Cambrian trilobites) might have been either digestive or respiratory tubes in the cephalon and other regions.<ref name=Clarkson98>{{Citation | last=Clarkson | first=E. N. K. |author-link=Euan Clarkson| year=1998 | title=Invertebrate Paleontology and Evolution | edition=4th | publisher=Wiley/Blackwell Science | location=Oxford | isbn=978-0-632-05238-7 | page=452 | url=https://books.google.com/books?id=g1P2VaPQWfUC&pg=PP1}}</ref>