Wikipedia
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.
Norops is a clade of 169 species of polychrotid lizards within the genus Anolis. Evidence for the clade's recognition stems from the fact that all of its designated species possess sufficient differences in morphology, especially in the structure and design of tail vertebrae, to suggest a deep divergence from the rest of Anolis. The exact position of Norops and other distinct species groups within Anolis, either as clades or as genera, has been a subject of ongoing debate among anole scientists, however the description of Norops and other clades as genera is rapidly losing support within the scientific community; however, it is unclear as to whether this debate will ever be completely resolved.