its outer margin evenly curved, and it has a narrow, well-defined border. It is about half as wide as the cephalon (micropygous), and about half as long as wide. Secondary sight Conocoryphe provides a rare (but not unique) example of secondary eye development. Conocoryphids lack eyes except for Conocoryphe oculata. This species is otherwise very similar to its relatives from the Montagne Noir region in France. C. oculata has normal curving eye ridges, although the dorsal suture is marginal like in its blind family. Due to poor preservation, lenses have not been found. It seems that the expression of a gene for eye development was only suppressed and not lost, and the eye could develop when the suppression lifted. References External links Conocoryphe at insectoid.info Ptychopariida genera Cambrian trilobites Fossils of the Czech Republic Fossils of France Fossils of Spain Fossils of Turkey Fossils of the United States