described ~1,900,000: undescribed 11,000,000 species
||Pimm SL et al., The biodiversity of species and their rates of extinction, distribution, and protection. Science. 2014 May 30 344(6187):1246752. doi: 10.1126/science.1246752. p.1 middle column 2nd paragraphPubMed ID24876501
|| A. D. Chapman, Numbers of Living Species in Australia and the World (Biodiversity Information Services, Toowoomba, Australia, 2009).
||P.1 middle column 2nd paragraph: "For animals, recent overviews attest to the question’s difficulty. About 1.9 million species are described (primary source) the great majority are not. Costello et al. (ref 8) estimate 5 ± 3 million species, Mora et al. (ref 9) 8.7 ± 1.3 million, and Chapman (primary source) 11 million. Raven and Yeates (BNID 113444) estimate 5 to 6 million species of insects alone, whereas Scheffers et al. (ref 11) think uncertainties in insect and fungi numbers make a plausible range impossible. Estimates for marine species include 2.2 ± 0.18 million (BNID 113445), and Appeltans et al. estimate 0.7 to 1.0 million species, with 226,000 described and another 70,000 in collections awaiting description (BNID 113445)."