Ctenosaura acanthura

The northeastern spinytail iguana was first described by British zoologist George Shaw in 1802.{{ITIS |id=585834 |taxon=Ctenosaura acanthura |accessdate=30 September 2008}} The generic name, Ctenosaura, is derived from two Greek words: ctenos (Κτενός), meaning "comb" (referring to the comblike spines on the lizard's back and tail), and saura (σαύρα), meaning "lizard".{{Citation|last=Malfatti|first=Mark|date=2007|title=A look at the genus Ctenosaura: meet the World's fastest lizard and its kin|journal=Reptiles Magazine|volume=15|issue=11|pages=64–73}}{{source needed|reason=Ancient Greek κτείς is comb, not 'ctenos'/κτενός. Nominative and genitive cases are confused.|date=June 2025}} Its specific name is the Greek word akanthos (Ἄκανθος), meaning "thorn".

Mexican spiny-tailed iguanas have distinctive keeled scales on their long tails, which give them their common name. The males are capable of growing up to {{convert|1.4|m|sp=us}} in total length and females slightly shorter at {{convert|1|m|sp=us}}. They have a crest of long spines which extends down the center of the back. Their base color is black with white or cream-colored markings.

Ctenosaura acanthura is often confused with the closely related and similar appearing black iguana (Ctenosaura similis); however, Ctenosaura acanthura does not occur in the Mexican states of Tabasco, Campeche, Yucatan, Quintana Roo, or in Belize (Yucatan Peninsula).Köhler, G. 2002. Schwarzleguane: Lebensweise, Pflege, Zucht. Herpeton, Verlag Elke Köhler, Offenbach, Germany. 142 pp.

{{rp| 128a p.}} Scales of the tail whorls on Ctenosaura acanthura are very thorny (an angle of the keels over 30 degrees), and the crest of large spines on the back is interrupted in the pelvic area, forming a break between the crest of large spines on the tail. On the black iguana (Ctenosaura similis), the crest of large spines on the back is uninterrupted and continuous with the large spines on the tail.{{rp| 59 p.}}{{rp| 144 p.}}

File:Ctenosaura acanthura, Mexican Spiny-tailed Iguana, Tamaulipas.jpg

Northeastern spinytail iguanas are excellent climbers and prefer a rocky habitat with plenty of crevices to hide in, rocks to bask on, and nearby trees to climb. They are diurnal and fast moving, employing their speed to escape predators but will lash with their tails and bite if cornered. This species may commonly be found around areas of human habitation.

{{citation | last = Hollingsworth | first = Bradford D. | title = The Evolution of Iguanas: An Overview and a Checklist of Species | work = Iguanas: Biology and Conservation | publisher = University of California Press | pages = 34–35 | date = 2004 | isbn = 978-0-520-23854-1 }}

They are primarily herbivorous, eating flowers, leaves, stems, and fruit, but they will opportunistically eat smaller animals, eggs, and arthropods. Juveniles tend to be insectivores, becoming more herbivorous as they get older.

File:Geographic distribution of three large species of lizards in the genus Ctenosaura (C. acanthura, C. pectinata, C. similis).jpg

Ctenosaura acanthura occurs in the lowlands on the eastern versant of Mexico throughout the Veracruz moist forests ecoregion and western portions of the Petén–Veracruz moist forests, from sea level up to ca. 1000 meters elevation. It is known from the Mexican state of Tamaulipas in the general vicinity of the Tropic of Cancer, southward throughout most of Veracruz, with a few records from lower elevation localities in adjacent areas of extreme eastern San Luis Potosi, Hidalgo, Pueblea, and Oaxaca. Southward, an apparently isolated population occurs in central Chiapas, in the Rio Grijalva valley, with a record extending the range into extreme western Guatemala.{{rp| 128a p.}}{{rp| 139–144 p.}}

The status of six specimens collected near the town of Sabinas Hidalgo, Nuevo Leon by Hobart M. Smith in 1934 is questionable, and C. acanthura has not been reported from Nuevo León before or after 1934. The presence of C. acanthura in Nuevo León is doubtful, and the collector (Hobart Smith) did not include the species in his checklist for the state of Nuevo León in later years.Lemos-Espinal, Julio A., Daniel B. Wylie, and Geoffrey R. Smith. 2017. New distributional records for reptiles from Nuevo León, Mexico. Herpetology Notes, 10: 639-641.Smith, H. M. and E. H. Taylor. 1966. Herpetology of Mexico: Annotated Checklist and Keys to the Amphibians and Reptiles. A reprint of Bulletins 187, 194 and 199 of the U. S. Nat. Mus. with a list of subsequent taxonomic innovations. Eric Lundberg, Ashton, Maryland.{{rp| 224 p.}}

File:Medical and physical researches, or, Original memoirs in medicine, surgery, physiology, geology, zoology, and comparative anatomy (1835) (14796571473).jpg

Mating generally occurs in the spring. A male shows dominance and interest by head bobbing, eventually chasing the female until he can catch her and subdue her. Within eight to ten weeks, the female will dig a nest and lay clutches of up to 24 eggs. The eggs hatch in 90 days, with the babies digging their way out of the sand. These juveniles are typically green with brown markings, although all-brown hatchlings have been recorded as well.{{citation | last = Köhler | first = Gunther | title = Notes on the systematic status of the taxa acanthura, pectinata, and similis of the genus Ctenosaura | journal = Senckenbergiana Biologica | date = 1996 | volume = 30 | issue = 1 | pages = 33–43}}

{{Reflist|2}}

• {{Wikispecies-inline|Ctenosaura acanthura}}
• {{usurped|1=[https://web.archive.org/web/20040408171725/http://westcoastiguana.com/acanthura.htm West Coast Iguana Research]}}

{{Iguanidae}}

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Category:Ctenosaura

Category:Lizards of Central America

Category:Reptiles of Mexico

Category:Reptiles of Guatemala

Category:Reptiles described in 1802

Category:Taxa named by George Shaw