Iguanidae T. Bell 1825 [O. Torres-Carvajal, K. de Queiroz and J. A. Schulte II], converted clade name Registration Number: 52 Alifanov (2000), Evans (2003), Conrad and Norell (2007), Conrad (2008, 2015), Longrich De!nition: !e largest crown clade contain- et al. (2012), and Smith and Gauthier (2013). ing Iguana (Lacerta) iguana (Linnaeus 1758) (Iguanidae), but not Agama (Lacerta) agama Diagnostic Apomorphies: Unambiguous mor- (Linnaeus 1758) (Agamidae) and Chamaeleo phological synapomorphies of Iguanidae have (Lacerta) chamaeleon (Linnaeus 1758) (Chamae- not been reported (Estes et al., 1988; Etheridge leonidae). !is is a maximum-crown-clade de"- and de Queiroz, 1988; Frost and Etheridge, nition. Abbreviated de"nition: max crown ∇ 1989; Gauthier et al., 2012); lists of characters (Iguana iguana (Linnaeus 1758) ~ Agama agama that change along the relevant branches are pro- (Linnaeus 1758) & Chamaeleo chamaeleon (Lin- vided by DeMar et al. (2017). naeus 1758)). Synonyms: Iguanoïdes Blainville (1816, 1822), Etymology: Derived from Iguana, the name Iguanae (Spix, 1825), Pachyglossae coelodontae of one of its subclades, which is based on the (Wagler, 1828), Pachyglossae platycormae pleur- Spanish “Iguana”, which is in turn derived from odontes + Pachyglossae stenocormae pleurodon- the Carib “iwana” (Burghardt and Rand, 1982). tes (Wagler, 1830), Iguanina Bonaparte (1831, 1840, 1841), Dendrobatae Prosphyodontes + Reference Phylogeny: Figure 6 of Estes et al. Humivagae Prosphyodontes (Wiegmann, 1834), (1988). For details concerning the composition Iguaniens Pleurodontes + Eunotes Pleurodontes and internal relationships see Etheridge and de (Duméril and Bibron, 1834–1854; Duméril and Queiroz (1988), Frost and Etheridge (1989), Duméril, 1851), Pleurodontes + Prosphyodontes Schulte et al. (2003), and Townsend et al. (Fitzinger, 1843), Iguanoidea + Agamida (2011), although some of those authors use the Pleurodonta (Stannius, 1856), Iguania (Cope, name Iguanidae for a smaller clade and call the 1864, 1875, 1889), Iguanida Strauch (1887), clade in question Pleurodonta (see Comments). and Pleurodonta (Frost et al., 2001) are all approximate synonyms. Composition: Iguanidae contains approxi- mately 1200 currently recognized extant species Comments: Early authors used diverse char- (Uetz, 2020) within 12 mutually exclusive clades acters to divide iguanian lizards (often exclud- (Schulte et al., 2003): Anolis, Corytophaninae, ing the highly modi"ed chamaeleons) into two Crotaphytinae, Hoplocercinae, Iguaninae, primary subgroups. !ose characters included Leiocephalus, Leiosaurini, Liolaemini, Oplurinae, compressed versus depressed body form (e.g., Phrynosomatinae, Polychrus, Tropidurini (some Wagler, 1830; Bonaparte, 1841), toothed ver- authors [e.g., Townsend et al., 2011] use names sus toothless palate (e.g., Gray, 1825; Cuvier, that all end in -idae for the same clades). A 1829; Bonaparte, 1831), tree climbing versus compilation of fossil Iguanidae can be found ground walking habits (e.g., Wiegmann, 1834; in Estes (1982), with subsequent additions in Fitzinger, 1843; Gravenhorst, 1843), and Iguanidae pleurodont versus “acrodont” tooth implanta- e#ective application to the crown. Moreover, the tion (e.g., Wagler, 1828; Duméril and Bibron, name Pleurodonta has at least three undesirable 1834–1854; Bonaparte, 1831; Gray, 1845; see properties. First, it describes an ancestral char- Estes et al. 1988 concerning tooth implantation acter state that is widely distributed outside of in supposedly acrodont iguanians). !e divi- the clade in question. Second, when used in the sion based on tooth implantation ultimately nineteenth century, the name was applied either prevailed, with the names Iguanidae (for the to a much less inclusive group (e.g., Stannius, pleurodont forms) and Agamidae (for the “acro- 1856) or, in keeping with the ancestral status dont” forms) being widely adopted from the and widespread distribution of pleurodonty, to late 1800s to the late 1900s (e.g., Boulenger, a much more inclusive one (e.g., Cope, 1864, 1885; Cope, 1900; Fürbringer, 1900; Gadow, 1875). !ird, it is a homonym of Pleurodonta 1901; Camp, 1923; Williston, 1925; Romer, Beck 1837, a name, applied to a taxon of mol- 1933, 1945, 1956, 1966; McDowell and lusks, that is not currently in use but is never- Bogert, 1954; Underwood, 1971; Estes, 1982; theless available under the ICZN (International Estes et al., 1988). By the late 1900s, authors Commission on Zoological Nomenclature, realized that pleurodonty is an ancestral char- 1999) and therefore could be converted under acter state and that morphological evidence for the ICPN. For all of these reasons, the name the monophyly of Iguanidae was lacking (e.g., Iguanidae is the more appropriate name for the Etheridge and de Queiroz, 1988; Estes et al., clade under consideration. 1988), which led to a proposal to abandon the Related to the alternative names for the clade taxon as previously circumscribed (Frost and in question, as well as to disagreements about Etheridge, 1989). Nonetheless, subsequent rank assignment under the ICZN, the name phylogenetic analyses of DNA sequences have Iguanidae has been applied to two di#erent found strong support for the monophyly of the clades in the recent literature. !us, when Frost Iguanidae as traditionally circumscribed (e.g., and Etheridge (1989; see also Frost et al., 2001) Macey et al., 1997; Schulte et al., 1998, 2003; rejected the traditional Iguanidae because of its Harris et al., 2001; Townsend et al., 2011; then-questionable monophyly, they restricted Pyron et al., 2013). that name, and its associated rank of family, Of the names previously applied to the clade to one of eight subgroups recognized by them- in question (see Synonyms), most have been selves and previous authors (e.g., Etheridge and rarely used after the nineteenth century, and de Queiroz, 1988). By contrast, other authors some of them are compound names and there- have preferred to apply the name Iguanidae to fore unsuitable for conversion (ICPN, Art. 17.1; the group with which it was traditionally asso- Cantino and de Queiroz, 2020). Only two ciated, at "rst with an explicit acknowledgment names have been applied to the clade during of its uncertain status (e.g., Estes et al., 1988; the last 100 years, Iguanidae and Pleurodonta. see also Zug, 1993; Schwenk, 1994), and later Of these two names, the former has been used under subsequently discovered support for its widely since the early 1900s, while the latter has monophyly (e.g., Macey et al., 1997; Harris et been used for the clade in question only since al., 2001; Schulte et al., 2003; Gauthier et al., Frost et al. (2001). Concomitant with this his- 2012). !is traditional use became established in torical di#erence, Iguanidae has been used far the nineteenth century (e.g., Gray, 1827, 1845; more commonly for a taxon approximating the Boulenger, 1884, 1885), was almost universal for clade for which we are establishing it, including most of the twentieth century (e.g., Cope, 1900; 1160 Iguanidae Gadow, 1901; Camp, 1923; Williston, 1925; Bonaparte, C. L. 1840. Prodromus systematis Romer, 1933, 1945, 1956, 1966; McDowell and herpetologiae. Nuovi Ann. Sci. Nat. Bologna Bogert, 1954; Underwood, 1971; Estes et al., 1988; 4:90–101. Bonaparte, C. L. 1841. A New Systematic Etheridge and de Queiroz, 1988), and continues Arrangement of Vertebrated Animals. Taylor, to be accepted by many authors (e.g., Macey et London. al., 1997; Harris et al., 2001; Schulte et al., 2003; Boulenger, G. A. 1884. Synopsis of the families Gauthier et al., 2012; Smith and Gauthier, 2013), of existing Lacertilia. Ann. Mag. Nat. Hist. including those of in$uential general works (e.g., 14:117–122. Zug et al., 2001; Pianka and Vitt, 2003; Pough Boulenger, G. A. 1885. Catalogue of the Lizards in et al., 2004). !is long-established use justi"es the British Museum (Natural History), Vol. 2. applying the name to the more inclusive clade. Taylor & Francis, London. Moreover, the smaller clade has been given a dif- Burghardt, G. M., and A. S. Rand. 1982. Iguanas of the World: !eir Behavior, Ecology, and ferent name, Iguaninae Cope 1886, which is one Conservation. Noyes Publications, Park Ridge, of the earliest names to have been given an explicit NJ. phylogenetic de"nition (de Queiroz, 1987). Camp, C. L. 1923. Classi"cation of the lizards. Under the ICPN, !omas Bell is considered Bull. Am. Mus. Nat. Hist. 48:289–481. the author of Iguanidae because he was the "rst Cantino, P. D., and K. de Queiroz. 2020. International author to use that name (Bell, 1825). Under the Code of Phylogenetic Nomenclature (PhyloCode), ICZN, Oppel (1811) is considered the author of Version 6. CRC Press, Boca Raton, FL. Iguanidae because his Iguanoides seems to have Conrad, J. L. 2008. Phylogeny and systematics of Squamata (Reptilia) based on morphology. been the "rst name based on the name Iguana Bull. Am. Mus. Nat. Hist. 310:1–182. proposed at the rank of family. Conrad, J. L. 2015. A new Eocene casquehead liz- ard (Reptilia, Corytophanidae) from North Literature Cited America. PLOS ONE 10(7):e0127900. Conrad, J. L., and M. A. Norell. 2007. A complete Alifanov, V. R. 2000. !e fossil record of Cretaceous Late Cretaceous iguanian (Squamata, Reptilia) lizards from Mongolia. Pp. 368–389 in !e from the Gobi and identi"cation of a new Age of Dinosaurs in Russia and Mongolia (M. iguanian clade. Am. Mus. Novit. 3584:1–47. J. Benton, M. A. Shishkin, D. M. Unwin, and Cope, E. D. 1864. On the characters of the higher E. N. Kurochkin, eds.). Cambridge University groups of Reptilia Squamata and especially of Press, Cambridge, UK. the Diploglossa. Proc. Acad. Nat. Sci. Phila. Beck, H. 1837. Index Molluscorum Præsentis 16:224–231. ævi Musei Principis Augustissimi Christiani Cope, E. D. 1875. Check-list of North American Frederici. Hafniæ. Batrachia and Reptilia; with a systematic list of Bell, T. 1825. On a new genus of Iguanidae. Zool. J. the higher groups, and an essay on geographi- 2:204–207. cal distribution. Based on the specimens con- de Blainville, H. D. 1816. Prodrome d’une nouvelle tained in the U.S.