Norops

Norops
Anolis polylepis, also called Norops polylepis, in Costa Rica, displaying a yellow dewlap
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Reptilia
Order:	Squamata
Suborder:	Lacertilia
Infraorder:	Iguania
Family:	Polychrotidae
Genus:	Norops Wagler, 1830
Species
c.150, see text

Norops is the proposed generic name for 150 lizard species traditionally classified in the genus Anolis (family, Iguanidae). Guyer and Savage (1986) applied this name to a group that Etheridge (1959) designated the "beta anoles" on the basis of skeletal characters that distinguished them from all other anole species (i.e., "the alpha anoles"). Although Norops is clearly a distinct, monophyletic group, it renders the "alpha anoles" paraphyletic. Guyer and Savage's proposed remedy for this problem involved the designation of four additional genera within the "alpha anoles". However, three of these genera are not supported as monophyletic by recent phylogenetic studies (Jackman et al. 1998, Poe 2004, Nicholson et al. 2005). As a result, recognition of Norops as a genus is premature and likely to confound efforts to study and conserve anoles. This position is stated explicitly in recent phylogenetic studies:

"Four of the Guyer and Savage genera have been shown to be paraphyletic (Poe, 1998; Jackman et al., 1999), and recognition of their remaining genus Norops would necessitate an entirely new Anolis taxonomy. Thus, their generic-level taxonomy is not followed here."—Poe 2004, p. 38

"The problem with recognizing Norops as a genus is that it necessarily renders Anolis (sensu lato) paraphyletic. Thus recognizing Norops as a genus is inappropriate..."—Nicholson 2002

In spite of these recommendations, Norops remains widely accepted by workers in mainland Central and South America. However, it is universally rejected by West Indian workers. These differences may be due to the fact the mainland fauna is dominated by only two deeply divergent clades (Norops and Dactyloa in Guyer and Savage's terminology), whereas the West Indian radiation is much more taxomically diverse, and relationships less certain. As a result, some members of Savage and Guyer's Anolis on Cuba are actually more closely related to Cuban species placed in Norops than they are to other Anolis, thus reinforcing the earlier point that recognition of Norops is too problematic to warrant its continued recognition.

Species of genus Norops^[1]

Norops poecilopus

References

Wikimedia Commons has media related to Norops.

• Guyer, C., & Savage, J. M. (1986). Cladistic relationships among anoles (Sauria: Iguanidae). Systematic Zoology, 35, 509-531
• Losos, J.B. (2009). Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation of Anoles. University of California Press:Berkeley, Ca.