Brachylophus

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Brachylophus
Brachylophus fasciatus.JPG
Fiji banded iguana (Brachylophus bulabula) in captivity
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Iguanidae
Genus: Brachylophus
Cuvier, 1829
Type species
Brachylophus fasciatus [ citation needed ]
Cuvier, 1829
Species

Brachylophus bulabula
Brachylophus fasciatus
Brachylophus gau
Brachylophus vitiensis
Brachylophus gibbonsi

Contents

Brachylophus sp. distribution.png

The genus Brachylophus consists of four extant iguanid species native to the islands of Fiji [1] and a giant extinct species from Tonga in the South West Pacific. [2] One of the extant species, B. fasciatus, is also present on Tonga, where it has apparently been introduced by humans. [2]

Etymology and taxonomy

The name, Brachylophus, is derived from two Greek words: brachys (βραχύς) meaning "short" and lophos (λόφος) meaning "crest" or "plume", denoting the short spiny crests found along the backs of these species.

Brachylophus species are the most geographically isolated iguanas in the world. Their closest extant relatives (the genera Amblyrhynchus , Conolophus , Ctenosaura , Cyclura , Iguana and Sauromalus [2] ) are present in primarily tropical regions of the Americas and islands in the Galápagos and Lesser and Greater Antilles. Several of these genera are adapted to xeric biomes. Phylogenetic evidence supports the Brachylophus lineage to have diverged from the rest of Iguanidae in the latest Eocene, about 35 million years ago. They are the second most basal extant genus in the family, with only Dipsosaurus diverging earlier. [3] The location of members of Brachylophus, so distant from all other known extant or extinct iguanids, has long presented a biogeographical enigma.

One hypothesis to account for this biogeographical puzzle, based in part on an estimated divergence date of 50 million years ago (although more recent studies have revised this to about 35 million years ago [3] ), is that these species are the descendants of a more widespread but now extinct lineage of Old World iguanids that migrated overland from the New World to Asia or Australia, and then dispersed by some combination of continental drift, rafting and/or land bridges to their present remote location. [4] However, no other fossil or extant species of this putative lineage have been found to date in Southeast Asia, Australasia or the western Pacific outside of Fiji and Tonga. [4]

A secondary hypothesis, and the more widely accepted one, is that these species evolved from New World iguanas that rafted 10,000 km (6,200 mi) west across the Pacific Ocean with the aid of the South Equatorial Current. [5] [6] While a rafting voyage of four months or more might seem implausible, the ancestors of Brachylophus may have been preadapted for such a journey by having water requirements that can be satisfied by food alone, as well as comparatively long egg incubation periods. [6]

Extant species

The extant species are: [1] [7]

ImageScientific nameCommon NameDistribution
Brachylophus bulabula Cologne Zoo.jpg Brachylophus bulabula Central Fijian banded iguanaNorthwestern islands of Fiji (Ovalau, Kadavu and Viti Levu)
Brachylophus fasciatus -Warsaw Zoo, Poland-8a.jpg Brachylophus fasciatus Lau banded iguanaEastern Fijian islands
GauIguanas.jpg Brachylophus gau Gau iguanaGau island
Fiji Crested Iguana444.jpg Brachylophus vitiensis Fiji crested iguanaNorthwestern islands of the Fijiian archipelago

Historically, only the first two were recognized, but B. bulabula ("bulabula" is the Fijian word for "healthy" or "flourishing") was described in the central regions of Fiji by a team led by a scientist from the Australian National University in 2008. Detailed genetic and morphological analyses were made to conclude that B. bulabula represents a third species. [2] [8] In 2017, B. gau was described as a new species from Gau Island. [1] [9]

A giant Tongan species, Brachylophus gibbonsi , similar in size and build to an iguana of the genus Cyclura once existed on Lifuka, islands in the Ha‘apai group and Tongatapu but became extinct in prehistoric times due to predation by humans and their domestic animals. [2] [10] [11] An even larger extinct iguana of the separate genus Lapitiguana was formerly present on Fiji. [12]

Related Research Articles

<span class="mw-page-title-main">Opluridae</span> Family of lizards

The Opluridae, or Madagascan iguanas, are a family of moderately sized lizards native to Madagascar and Grande Comore. There are eight species in two genera, with most of the species being in Oplurus. The Opluridae, along with Brachylophus of Fiji, are the only extant members of the Pleurodonta that are found outside the Americas.

<span class="mw-page-title-main">Iguanidae</span> Family of lizards

The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana.

<i>Ctenosaura</i> Genus of lizards

Ctenosaura is a lizard genus commonly known as spinytail iguanas or ctenosaurs. The genus is part of the large lizard family, Iguanidae and is native to Mexico and Central America. The name is derived from two Greek words: κτενός, meaning "comb", and σαύρα, meaning "lizard".

<span class="mw-page-title-main">Iguanomorpha</span> Infraorder of lizards

Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, the Iguania are believed to form the sister group to the remainder of the Squamata, which comprise nearly 11,000 named species, roughly 2000 of which are iguanians. However, molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha and closely related to snakes. The order has been under debate and revisions after being classified by Charles Lewis Camp in 1923 due to difficulties finding adequate synapomorphic morphological characteristics. Most Iguanias are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. The group has a fossil record that extends back to the Early Jurassic. Today they are scattered occurring in Madagascar, the Fiji and Friendly Islands and Western Hemisphere.

<i>Brachylophus fasciatus</i> Species of lizard

Brachylophus fasciatus, the Lau banded iguana, is an arboreal species of lizard endemic to the Lau Islands of the eastern part of the Fijian archipelago. It is also found in Tonga, where it was probably introduced by humans. It is one of the few species of iguanas found outside of the New World and one of the most geographically isolated members of the family Iguanidae. Populations of these iguanas have been declining over the past century due to habitat destruction, and more significantly, the introduction of mongoose and house cats to the islands.

<i>Ctenosaura bakeri</i> Species of lizard

Ctenosaura bakeri, also known as the Utila spiny-tailed iguana, Baker's spinytail iguana, swamper or wishiwilly del suampo, is a critically endangered species of spinytail iguana endemic to the island of Utila, one of the Islas de la Bahía off the coast of Honduras in the Caribbean.

<span class="mw-page-title-main">Fiji crested iguana</span> Species of lizard

The Fiji crested iguana or Fijian crested iguana is a critically endangered species of iguana native to some of the northwestern islands of the Fijiian archipelago, where it is found in dry forest on Yaduataba, Yadua, Macuata, Yaquaga, Devuilau, Malolo, Monu and Monuriki.

In phylogenetics, basal is the direction of the base of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa.

<i>Ctenosaura melanosterna</i> Species of reptile

Ctenosaura melanosterna, commonly known as the black-chested spiny-tailed iguana or Honduran spinytailed iguana, is a species of lizard in the family Iguanidae.

<i>Ctenosaura oedirhina</i> Species of lizard

Ctenosaura oedirhina, commonly known as the Roatán spiny-tailed iguana or de Queiroz's spiny-tailed iguana, is a species of lizard in the family Iguanidae. It is endemic to Honduras, on the island of Roatán in the Caribbean, to which one of its common names refers. The Roatán iguana is a medium sized iguana with a rounded snout, short crest scales, and a snout-vent length ranging from 151 to 325mm.

<i>Cyclura nubila</i> Species of reptile

The Cuban rock iguana, also known as the Cuban ground iguana or Cuban iguana, is a species of lizard of the iguana family. It is the second largest of the West Indian rock iguanas, one of the most endangered groups of lizards. A herbivorous species with a thick tail and spiked jowls, it is one of the largest lizards in the Caribbean.

<i>Cyclura</i> Genus of lizards

Cyclura is a genus of lizards in the family Iguanidae. Member species of this genus are commonly known as "cycluras" and only occur on islands in the West Indies. Rock iguanas have a high degree of endemism, with a single species or subspecies originating on an individual island.

<i>Brachylophus bulabula</i> Species of lizard

Brachylophus bulabula, commonly known as the Central Fijian Banded Iguana is a species of iguanid lizard endemic to some of the larger central and northwestern islands of Fiji, where it occurs in Fijian wet forest. It was described by a team led by a scientist from the Australian National University in 2008. It is one of the few species of iguana found outside of the New World and one of the most geographically isolated members of the family Iguanidae. Initially also reported from Gau Island, in 2017 this population was described as a separate species, B. gau. They can grow up to 2 feet long and have an average lifespan of 10-15 years. However, there have been some captive Fiji banded iguanas that have lived as long as 25 years. Fijian banded iguana typically are found in tropical wet islands that are typically 650-1700 feet above sea level. They also like to bask in temperatures ranging from 75–95 °F (24–35 °C). The areas that are most suitable for Fiji banded iguanas are Viti Levu, Vanua Levu, Ovalau, Viwa, and Kadavu. Males are typically are green with blue stripes and the females are green with white stripes.

<span class="mw-page-title-main">Oceanic dispersal</span> Biological dispersal across oceans

Oceanic dispersal is a type of biological dispersal that occurs when terrestrial organisms transfer from one land mass to another by way of a sea crossing. Island hopping is the crossing of an ocean by a series of shorter journeys between islands, as opposed to a single journey directly to the destination. Often this occurs via large rafts of floating vegetation such as are sometimes seen floating down major rivers in the tropics and washing out to sea, occasionally with animals trapped on them. Dispersal via such a raft is sometimes referred to as a rafting event. Colonization of land masses by plants can also occur via long-distance oceanic dispersal of floating seeds.

<i>Lapitiguana</i> Extinct genus of lizards

Lapitiguana impensa is an extinct giant iguanid from Fiji. It probably became extinct following the human colonization of Fiji 3000 years ago.

<i>Brachylophus gibbonsi</i> Extinct species of lizard

Brachylophus gibbonsi is an extinct species of large iguanid lizard from Tonga in the South Pacific Ocean. Its remains have been found associated with cultural sites on Lifuka, four other islands in the Haʻapai group, and Tongatapu. It was consumed by the early Tongans and probably became extinct within a century of human colonization of the archipelago 2800 years ago.

Lepidosaur herbivory describes herbivorous lepidosaurs. Living non-avian reptiles form a paraphyletic group that consists of over 9,000 species of crocodiles, turtles, and lepidosaurs. The most diverse group, Lepidosauria, is first known from the Middle Triassic fossils, but likely originated in the Permian. Living lepidosaurs, which include snakes, lizards, and rhynchocephalians, occupy a wide range of environments and niches. The lepidosaurs have many similar anatomical morphology like transverse cloaca, distal tongue, superficial teeth attachment, fused pelvic bones etc. Though widely viewed as obligate carnivores, a small number of lepidosaurs are known to consume plant material. For example, there are roughly 3,300 species of living lizards and approximately 3% of them eat at least some plants. Though the exact definition of herbivory varies significantly between scientists, most define herbivorous lepidosaurs as those that consume plants for approximately 70-90% of its diet.

<span class="mw-page-title-main">Gau iguana</span> Species of lizard

The Gau iguana is a species of iguana endemic to Gau Island in the Fijian archipelago. It mostly lives in the well-preserved upland forests of the island, with smaller populations in the degraded coastal forests. It can be distinguished from other South Pacific iguanas by the male's distinctive color pattern and solid green throat. It is also the smallest of all South Pacific iguanas, being about 13% smaller than the third smallest species and 40% smaller than the largest extant species.

References

  1. 1 2 3 Fisher, R. N.; Niukula, J.; Watling, D.; Harlow, P. S. (2017). "A New Species of Iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands". Zootaxa. 4273 (3): 407–422. doi: 10.11646/zootaxa.4273.3.5 . PMID   28610241 . Retrieved 2018-08-14.
  2. 1 2 3 4 5 Keogh, J. Scott; Edwards, Danielle L.; Fisher, Robert N.; Harlow, Peter S. (2008-10-27). "Molecular and morphological analysis of the critically endangered Fijian iguanas reveals cryptic diversity and a complex biogeographic history". Philosophical Transactions of the Royal Society B: Biological Sciences . 363 (1508): 3413–3426. doi:10.1098/rstb.2008.0120. PMC   2607380 . PMID   18782726.
  3. 1 2 Malone, Catherine L.; Reynoso, Víctor Hugo; Buckley, Larry (2017-10-01). "Never judge an iguana by its spines: Systematics of the Yucatan spiny tailed iguana, Ctenosaura defensor (Cope, 1866)". Molecular Phylogenetics and Evolution. 115: 27–39. doi:10.1016/j.ympev.2017.07.010. ISSN   1055-7903. PMID   28716742.
  4. 1 2 Noonan, B. P.; Sites, J. W. Jr. (2009-11-24). "Tracing the origins of iguanid lizards and boine snakes of the Pacific". The American Naturalist . 175 (1): 61–72. doi:10.1086/648607. PMID   19929634. S2CID   5882832.
  5. Cogger, Harold (1974). "Voyage of the Banded Iguana". Australia Natural History. 18 (4): 144–149.
  6. 1 2 Gibbons, J. R. H. (1981-07-31). "The biogeography of Brachylophus (Iguanidae) including the description of a new species, B. vitiensis, from Fiji". Journal of Herpetology. 15 (3): 255–273. doi:10.2307/1563429. JSTOR   1563429.
  7. Brachylophus at the Reptarium.cz Reptile Database. Accessed 23 March 2017.
  8. Cooper, Dani (2008-09-16). "Hello, it's a new species of Pacific iguana". ABC Science. Australian Broadcasting Corporation . Retrieved 2010-09-28.
  9. "Scientists Discover New Species of Fijian Iguana". USGS. 6 June 2017. Retrieved 9 June 2017.
  10. Pregill, Gregory K.; Dye, Tom (1989). "Prehistoric extinction of giant iguanas in Tonga". Copeia . 1989 (2): 505–508. doi:10.2307/1445455. JSTOR   1445455.
  11. Pregill, G. K.; Steadman, D. W. (March 2004). "South Pacific iguanas: Human impacts and a new species". Journal of Herpetology . 38 (1): 15–21. doi:10.1670/73-03A. JSTOR   1566081. S2CID   85627049.
  12. Pregill, G. K.; Worthy, T. H. (March 2003). "A new iguanid lizard (Squamata, Iguanidae) from the Late Quaternary of Fiji, Southwest Pacific". Herpetologica. 59 (1): 57–67. doi:10.1655/0018-0831(2003)059[0057:ANILSI]2.0.CO;2. S2CID   85804786. Archived from the original on 2022-04-27. Retrieved 2017-12-13.