Pigmented anatomy in Carboniferous cyclostomes and the evolution of the vertebrate eye.

ABSTRACT: The success of vertebrates is linked to the evolution of a camera-style eye and sophisticated visual system. In the absence of useful data from fossils, scenarios for evolutionary assembly of the vertebrate eye have been based necessarily on evidence from development, molecular genetics and comparative anatomy in living vertebrates. Unfortunately, steps in the transition from a light-sensitive 'eye spot' in invertebrate chordates to an image-forming camera-style eye in jawed vertebrates are constrained only by hagfish and lampreys (cyclostomes), which are interpreted to reflect either an intermediate or degenerate condition. Here, we report-based on evidence of size, shape, preservation mode and localized occurrence-the presence of melanosomes (pigment-bearing organelles) in fossil cyclost

SUBMITTER: Gabbott SE 

PROVIDER: S-EPMC5013770 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature