Iwabe, N.; Hara, Y.; Kumazawa, Y.; Shibamoto, K.; Saito, Y.; Miyata, T.; Katoh, K. (29 de diciembre de 2004). «Sister group relationship of turtles to the bird-crocodilian clade revealed by nuclear DNA-coded proteins». Molecular Biology and Evolution22 (4): 810-813. PMID15625185. doi:10.1093/molbev/msi075.
Chapman, Arthur D. (2009). Numbers of Living Species in Australia and the World(en inglés) (2ª edición). Canberra, Australia: Australian Biological Resources Study. p. 80. ISBN9780642568618. Consultado el 26 de agosto de 2011. «Mammals are a quite well known group, however estimates for the numbers of described species still vary considerably, ranging from 4300 in Biodiversity: the UK Action Plan (Anon. 1994), through 4630 (Groombridge and Jenkins 2002), 5416 (IUCN 2004), 5419 (Wilson and Reeder 2005) to 5487 (IUCN 2009a). For the purposes of this report, I have accepted the figure of 5487 which accords well with the most recent figures from The IUCN Red List of Threatened Species although Hilton-Taylor (pers. comm. 17) suggests that there are several additional recently described species.»
Iwabe, N.; Hara, Y.; Kumazawa, Y.; Shibamoto, K.; Saito, Y.; Miyata, T.; Katoh, K. (29 de diciembre de 2004). «Sister group relationship of turtles to the bird-crocodilian clade revealed by nuclear DNA-coded proteins». Molecular Biology and Evolution22 (4): 810-813. PMID15625185. doi:10.1093/molbev/msi075.