Australia: The Land Where Time Began

A biography of the Australian continent 

Cambrian Explosion - Morphology of Cambrian Lobopodian Eyes from the Chengjiang Lagerstätte and Their Evolutionary Significance¹

A great diversity of morphologies is exhibited by visual organs that are widely distributed throughout the animal kingdom. The oldest visual system of arthropods that have been preserved are compound eyes made up of many ommatidia (visual units), though their origins are obscure and models of their origins that are hypothetical have been difficult to test as there is no known fossil evidence that is unequivocal. In this paper the authors¹ present the detailed eye structures found in lobopodians of Cambrian age recovered from the Chengjiang Lagerstätte, China, in 2 forms, Luolishania longicruris and Hallucigenia fortis. These animals have a pair of eyes that are composed of at least 2 visual units that have been interpreted as pigment cups. Previously it had been suggested that lobopodians from the Cambrian had ocellus-like eyes that were comparable to those of extant onychophorans but these eyes of multicomponent structure are more similar to the lateral eyes found in arthropods. These lobopodian eyes may, as indicated by morphological comparison and phylogenetic analyses, represent an early evolutionary stage of the ancestral Euarthropod visual system.

See Fossil Eyes

Sources & Further reading

1. Erwin, Douglas H., & Valentine, James W., 2013, The Cambrian Explosion: The Construction of Animal Biodiversity, Roberts & Co., Greenwood Village, Colorado