Fraction of species known today that have image-forming eyes

Range ~96 %
Organism Metazoa animals
Reference Fernald RD. Casting a genetic light on the evolution of eyes. Science. 2006 Sep 29 313(5795):1914-8 DOI: 10.1126/science.1127889 p.1914 middle column top paragraphPubMed ID17008522
Primary Source [2] M. F. Land, D.-E. Nilsson, Animal Eyes (Oxford Animal Biology Series, Oxford Univ. Press, Oxford, 2002), pp. 1–15.
Comments P.1914 left column bottom paragraph: "Image-forming eyes appeared in 6 of the 33 extant metazoan phyla (Cnidaria, Mollusca, Annelida, Onychophora, Arthropoda, and Chordata), and these six contribute about 96% of the known species alive today (primary source)."
Entered by Uri M
ID 117179