The Opluridae, or Madagascan iguanas, are a family of moderately sized lizards native to

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

and

Grande Comore Grande Comore () is an island in Comoros off the coast of Africa. It is the largest island in the Comoros nation. Most of its population is of the Comorian ethnic group. Its population is about 316,600. The island's capital is Moroni, Comoros, ...

. There are eight

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in two

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

, with most of the species being in ''Oplurus''. The Opluridae, along with ''

Brachylophus The genus ''Brachylophus'' consists of four extant iguanid species native to the islands of Fiji and a giant extinct species from Tonga in the South West Pacific. One of the extant species, ''B. fasciatus'', is also present on Tonga, where it ha ...

'' of

Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...

, are the only extant members of the

Pleurodonta Pleurodonta (from Greek '' lateral teeth'', in reference to the position of the teeth on the jaw) is one of the two subdivisions of Iguania, the other being Acrodonta ('' teeth on the top f the jaw'). Pleurodonta includes all families previously ...

that are found outside the Americas. The family includes species that live amongst rocks, some that live in

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s, and two that prefer sandy habitats. All of the species lay

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

, and have teeth that resemble those of the true

iguana ''Iguana'' (, ) is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his bo ...

s. A study was done to identify the foraging mode of the ''Oplurus'' species. The species was highly favored to be ambush foragers due to their low movement per min (MPM) and percent time spent moving (PTM) During rainy and dry seasons of the jardin botanique A of Ampijoroa forest. the two genera are easily distinguished. The smaller two '' Chalarodon'' species have a dorsal crest, particularly distinct in males, and has a smoother tail covered in similarly sized scales. Genus ''

Oplurus ''Oplurus'' is a genus of Malagasy iguanian lizards, most of which are rock-dwelling terrestrial species. The sister genus to ''Oplurus'' is ''Chalarodon'', which contains two species: '' Chalarodon madagascariensis'' and '' Chalarodon steink ...

'' has large segmented spiny scales, and no dorsal crest along the spine. Schlüter, Uwe (2013). "''Madagaskarleguane - Lebensweise, Pflege und Fortpflanzung''". ''KUS-Verlag, Rheinstetten''. . A Monograph on Opluridae (in

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

). Previously, due to their isolation from all other iguanians, it was thought that oplurids had very ancient origins. A study of

mitochondria A mitochondrion (; ) is an organelle found in the Cell (biology), cells of most Eukaryotes, such as animals, plants and Fungus, fungi. Mitochondria have a double lipid bilayer, membrane structure and use aerobic respiration to generate adenosi ...

l DNA sequences had dated the split between Opluridae and Iguanidae (within which Opluridae are sometimes classified as the subfamily Oplurinae) at about 165 million years ago, during the

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

. The study supported the

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of the expanded Iguanidae, and put Oplurinae in the basal position. This dating was consistent with a

vicariant Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

origin of the Madagascan iguanians, since Madagascar is believed to have separated from

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

(during the breakup of Gondwana) around 140 million years ago. However, a 2022 study found Opluridae to be the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the

Leiosauridae Leiosauridae is a family of iguanian lizards containing six genera and 34 species. The family is endemic to Central America and South America. Taxonomy A 2022 phylogenetic study found the Leiosauridae to be the sister taxa to the Opluridae, a ...

, a family of iguanians found in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. Both groups were found to have only diverged during the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

, about 60 million years ago. As this divergence was too recent to be a result of vicariance, it was proposed that the Opluridae colonized Madagascar via

oceanic dispersal 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 island ...

, either directly from South America to Madagascar, or from South America to either Africa or

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

(not yet glaciated at the time), and then from there to Madagascar.

Species

Family Opluridae * Genus '' Chalarodon'' ** '' Chalarodon madagascariensis'' ** '' Chalarodon steinkampi'' * Genus ''

'' ** '' Oplurus cuvieri'' ** '' Oplurus cyclurus'' ** '' Oplurus fierinensis'' ** '' Oplurus grandidieri'' ** '' Oplurus quadrimaculatus'' ** '' Oplurus saxicola''

References

External links

Family Opluridae
Lizard families Extant Middle Jurassic first appearances Callovian first appearances {{lizard-stub