Anegada Iguana (Cyclura pinguis) Fact Sheet: Taxonomy & History

Taxonomic History and Nomenclature

• Scientific name: Cyclura from the Greek kyklos or "circle" and oura or "tail," and penguis from the Greek for "fat" (not for appearance, but in sense of "fatty", "oily" or "greasy" (Parker 2010)
• Common name: Anegada Island Iguana named for island it inhabits in West Indies; also called Stout Iguana for its robust body shape or Anegada Rock Iguana for its preference for retreats in limestone crevices; also Anegada Ground Iguana
• Within the Order Squamata, iguanian lizards divide into two groups by their teeth (Cracraft & Donoghue 2004)
  • Pleurodonts (around 470 species, including rock or ground iguanas - teeth fused to the inner side of the jaw bones)
  • Acrodonts (around 535 species - teeth on outer rim of jaw)
  • All species usually have fleshy dewlap on chin, with crests or ornaments on head and body
• The family Iguanidae is the largest of the lizard families, containing some 60 genera and 600 species. (Etheridge & de Queiroz 1988)
• Debate exists over placement of various iguana groups as subfamilies, or as distinct families. (Hollingsworth 2004) (Frost et al 2001).
  • Iguanas do share similar skeletal morphology, behavior, digestive systems and DNA (Hollingsworth 2004)
• Also share lingual prehension (tongue grasps food, pulls into mouth), dependence on visual cues (Vidal & Hedges 2005)
• Lazell (2005) argues that the two genera, Cyclura and Iguana, should be united because their species have few consistent differences; de Queiroz (1987) and Norell and de Queiroz (1991) see anatomical distinctions between the two genera.

• Major diversification in squamate (lizard + snake) reptiles occurred by 250 to 150 million years ago. (Vidal & Hedges 2005)
• A new fossil discovery from India suggests lizards existed at least 200 million years ago (Late Triassic) (Datta & Ray 2006)
• Other evidence from mitochondrial DNA suggests that by around 200 million years ago Iguanidae had already diverged from other squamates. (Okajima & Kumazawa 2010)
• Various lizard families diverged much earlier and are much older than families of birds and mammals (Kumazawa 2006)
• Two major categories of iguana-like animals existed by 160 million years ago. (Macey et al 1997)
  • Acrodont lizards (with teeth attached to the ridge of the jawbone, without sockets)
  • All other lizards (teeth in groove on inner surface of jaw)
• Vertebrate animals in the West Indies swam from far-off bodies of land sometime after 64 million years ago when the Late Cretaceous meteorite impact wiped out local floras and faunas. (Hedges et al 1992)
• Based on DNA molecular clocks, the genus Cyclura colonized the Caribbean around 35 to 15 million years ago (Oligocene-Miocene). (Malone et al 2000)
• Cyclura is not closely related to any other lizard genus; it evolved from a single ancestor (monophyletic) (Malone et al 2000)
  • The most ancient lineages of Cyclura are found on Puerto Rican Bank
  • Colonization of West Indian islands proceeded northwesterly
  • Anegada iguana (C. pinguis) is the basal Cyclura species (either at bottom of family tree or is a close relative of iguana from which all other Cyclura evolved). (Lazell 2005) (Wiens & Hollingsworth 2000)
• Cyclura sp. fossils found only in Pleistocene sites on the Cayman Islands and Puerto Rico (Schettino 1999)
• Anegada Island iguana (C. pinguis) fossils appear in late Pleistocene (15,000 - 20,000 years old) sites in Puerto Rico (Perry & Gerber 2006) (Pregill 1981)
• Anegada Island iguanas still have considerable genetic diversity, perhaps because their number have declined markedly only recently. (Malone & Davis 2004)

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia (Laurenti, 1768) - reptiles

Order: Squamata (Oppel, 1811)

Family: Iguanidae - Iguanas, iguanids, chuckwallas, and American arboreal lizards

Genus: Cyclura (Harland, 1825)

Species: Cyclura pinguis (Barbour, 1917) - Anegada (Island/Ground/Rock) Iguana

Source: Integrated Taxnomic Information System (2017)

Cracraft & Donoghue (2004)
de Queiroz (1987)
Estes (1983)
Frost et al. (2001)
Hedges et al. (1992)
Hollingsworth (2004)
ITIS (2010)
Lazell (2005)
Macey et al. (1997)
Malone et al. (2000)
Norell and de Queiroz (1991)
Pregill (1981)
Wiens & Hollingsworth (2000)

A male Anegada Iguana in the wild.

Image credit: © Jeff Lemm. All rights reserved. Used with permission from the artist.