Anolis? Norops? Dactyloa?
Updated: Mar 14
"The Controversial Case of Anolis: The Debate on Taxonomic Classification".
Taxonomy is the part of systematics that deals with the classification or arrangement in groups of elements that have common characteristics, which applied to biology, tries to create an order in the apparent chaos of living beings. But taxonomy is not an exact science. It has been tried since the time of Linnaeus (1758) to name (based on a genus and a species, arranged in families, orders and classes) all possible living beings, and in this task some authors have not agreed with others, for which reason given that some names of families, genera and species are named by some in one way, and by others in another.
In the 2000s there was a revolution in taxonomy (due to new molecular techniques being refined more and more accurately), changing a great deal of the previous ordering or taxonomy [which was usually based on phenetics, that is, their superficial similarity], or morphological) to a more comprehensive one that took into account various aspects inherent to living beings, such as anatomy, physiology, genetics and bioacoustics, under an integrative methodology.
This meant major changes in the systematics, and to name just a few of the most notorious, it went from naming all the typical toads of the genus Bufo to a host of genera (Rhinella, Incilius, Rhaebo, Anaxyrus, etc.), always leaving the original genus for the type species and allies of the same lineage (Bufo only for the Old World toads of the bufo group; eg Bufo bufo, B. spinosus, B. japonicus, B. verrucosissimus, etc.). The same with the genus Hyla, where until 2005 with the revision of Julián Faivovich, almost all the species of tree frogs entered; Hyla remained for the Eurasian species, while the Neotropical ones were divided into Boana, Dendropsophus, Hyloscirtus, etc). Same for poison dart frogs as before the review by Taran Grant et al. (2006) were almost all in Dendrobates (now Dendrobates is only the lineage with the type species of the genus, D. tinctorius and related: D. leucomelas, D. auratus, D. truncatus...), splitting other species into several other genera: Ranitomeya, Oophaga, Andinobates, Ameerega, Excidobates, etc… In the same way, there were profound changes in the taxonomy of the Squamata (scaly sauropsids), and genera that had been historically well determined began to divide into many others. For example, the genus of Scincidae Mabuya, after the revision of Hedges & Conn in 2012, passed to multiple genera, such as Marisora, Maracaiba, Orosaura, Trachylepis, etc, leaving Mabuya for the Caribbean lineage, since the type species of Mabuya is Mabuya mabouya from the island of Martinique in the Caribbean. And many other examples…
But despite the initial reluctance of many authors to follow these divisions, sometimes quite traumatic (based simply on a romanticism or habit that science should lack), little by little the world of biology has been compacted and convinced of the need and usefulness of using an updated systematics based on cladistics (which is what in biology defines the evolutionary relationships between organisms based on derived similarities).
Another very striking case that still generates discrepancies is Anolis. Anolis (in the broad sense or sensu lato) is the second most diverse genus of vertebrates, with over 500 species (after the amphibian genus Pristimantis, with more than 550 species, roughly). But like the genera Bufo, Hyla, Dendrobates, Mabuya and others, there have also been attempts to classify them into phylogenetic lineages based on morphology and genetics. The oldest was that of Guyer & Savage in 1986, based on previous work by Etheridge and Williams, which recognized the genera Anolis (sensu stricto), Ctenonotus, Dactyloa, Norops, and Semiurus (later replaced by Xiphosurus, a senior synonym). His conclusions were re-evaluated in 1992 (Guyer & Savage 1992). Since then, some later researchers (Crother, Jackman, Losos, Hedges, etc) tried to refine the systematics without much success. Steven Poe in 1998 takes a conservative position that he has maintained to date, in which he prefers to maintain a single Anolis genus (sensu lato) even while recognizing that it is not monophyletic. It is Kirsten Nicholson, a student of Jay Savage, who in 2002 and later, especially in 2012, presented a new classification of the Dactyloidae, meriting the extensive previous work of so many authors. However, and despite the solid evidence that deserves the separation of Anolis into several genera (Dactyloa, Deiroptyx, Chamaelinorops, Xiphosurus, Ctenonotus, Audantia, Norops and Anolis), Poe especially becomes detractor for reasons that only he knows (possibly the fact that working with a single genus instead of several makes you more famous or it is easier to get scholarships). In several rude articles, he proposes that Nicholson's conclusions should be taken as a joke, despite the fact that he himself uses the partition at his convenience (Poe 2004, 2013, 2017). Unfortunately, the use of a single genus obscures the understanding of evolution and diversity within the group and covers it up. Fortunately, Nicholson in 2018 sentenced the issue by returning the proper use of genres in the family.
Recently, the name of the family that contains them has also changed, from Dactyloidae to Anolidae (de Queiroz 2022).
In summary, despite the negligence of many authors, especially South Americans, who prefer to continue using a genus only in the face of the tremendous evidence of non-monophyly of the family Anolidae, several weighty authors such as J. Savage, K. Nicholson, B. Hedges, G Kohler, J. Johnson, L. Wilson, etc, prefer to adopt the most logical system using generic names for the different evolutionary lineages that are expressed in all these works mentioned.
de Keiroz, K. (2022) The Correct Name for the Taxon Ranked as a Family Containing the Genus Anolis under Rank-based Nomenclature and the Author of the Name Anolis loysiana. Herpetological Review 53(3), 418–420.
Jackman, T.R., Larson, A., de Queiroz, K. & Losos, J.B. (1999) Phylogenetic relationships and tempo of early diversification in Anolis lizards. Systematic Biology, 48, 254–285.
Johnson, J.D., Mata-Silva, V. & Wilson, L.D. (2015) A conservation reassessment of the Central American herpetofauna based on the EVS measure. Amphibian & Reptile Conservation 9(2), 1–94.
Nicholson, K.E. (2002) Phylogenetic analysis and a test of the current infrageneric classification of Norops (Beta Anolis). Herpetological Monographs, 16, 93–120.
Nicholson, K.E., Harmon, L.J., & Losos, J.B. (2007) Evolution of Anolis lizard dewlap diversity. PLoS ONE, 2(3): e274. doi:10.1371/journal.pone.000027
Nicholson, K.E., Crother, B.I., Guyer, C. & Savage, J.M. (2012) It is time for a new classification of anoles. Zootaxa, 3477, 1–108.
Nicholson, K.E., Crother, B.I., Guyer, C. & Savage, J.M. (2018) Translating a clade based classification into one that is valid under the international code of zoological nomenclature: the case of the lizards of the family Dactyloidae (Order Squamata). Zootaxa 4461(4): 573–586.
Nicholson, K.E., Crother, B.I., Guyer, C. & Savage, J.M. (2014) Anole classification: a response to Poe. Zootaxa, 3814 (1), 109–120.
Poe, S. (2004) Phylogeny of anoles. Herpetological Monographs, 18, 37–89.
Poe, S., Nieto-Montes de Oca, A., Torres-Carvajal, O., de Queiroz, K., Velasco, J.A., Truett, B., Gray, L.N., Ryan, M.J., Köhler, G., Ayala-Varela, F. & Latella, I. (2017) A phylogenetic, biogeographic, and taxonomic study of all extant species of Anolis (Squamata; Iguanidae). Systematic Biology, 66 (5), 663–697.
Savage, J.M. & Guyer, C. (1989) Infrageneric classification and species composition of the anole genera, Anolis, Ctenonotus, Dactyloa, Norops and Semiurus. Amphibia-Reptilia, 10, 105–116.
Savage, J.M. & Guyer, C. (1991) Nomenclatural notes on Anolis (Sauria: Polychrotidae): stability over priority. Journal of Herpetology, 23, 365–366.
Savage, J.M. & Guyer, G. (2004) Application of anole lizard generic names proposed by Wagler, 1830 and Fitzinger, 1843. Amphibia-Reptilia, 25, 303–305.
Williams, E.E. (1976b) South American anoles: the species groups. Papeis Avulsos Zoologia, 29, 259–268.
Williams, E.E. (1989) A critique of Guyer and Savage (1986): cladistic relationships among anoles (Sauria: Iguanidae): are the data available to reclassify the anoles? In: Woods, C.A. (Ed.) Biogeography of the West Indies: Past, Present, Future. Sandhill Crane Press, Gainesville, FL. pp. 433–477.