''Draco'' is a

genus 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 nom ...

agamid Agamidae is a family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview Phylogenetically, they may be sister to the ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia altho ...

s that are also known as flying lizards, flying dragons or gliding lizards. These lizards are capable of

gliding flight Gliding flight is heavier-than-air flight without the use of thrust; the term volplaning also refers to this mode of flight in animals. It is employed by gliding animals and by aircraft such as gliders. This mode of flight involves flying a s ...

via membranes that may be extended to create wings ( patagia), formed by an enlarged set of ribs. They are

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

insectivores. While not capable of powered flight they often obtain lift in the course of their gliding flights. Glides as long as have been recorded, over which the animal loses only in height, which is quite some distance, considering that one lizard is only around in total length, tail included. Piper, Ross (2007). 'Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals'. Santa Barbara, California:

Greenwood Press Greenwood Publishing Group, Inc. (GPG), also known as ABC-Clio/Greenwood (stylized ABC-CLIO/Greenwood), is an educational and academic publisher (middle school through university level) which is today part of ABC-Clio. Established in 1967 as Gr ...

. They are found across Southeast Asia and southern India. and are fairly common in forests,

areca ''Areca'' is a genus of 51 species of palms in the family Arecaceae, found in humid tropical forests from the islands of the Philippines, Malaysia and India, across Southeast Asia to Melanesia. The generic name ''Areca'' is derived from a name u ...

gardens,

teak Teak (''Tectona grandis'') is a tropical hardwood tree species in the family Lamiaceae. It is a large, deciduous tree that occurs in mixed hardwood forests. ''Tectona grandis'' has small, fragrant white flowers arranged in dense clusters ( pan ...

plantations and shrub jungle.

History of discovery

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...

described the genus in 1758, with the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

being ''

Draco volans ''Draco volans'', also commonly known as the common flying dragon, is a species of lizard in the family Agamidae. The species is endemic to Southeast Asia. www.reptile-database.org. Like other members of genus ''Draco'', this species has the ab ...

.'' The name of the genus is from the

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

term for mythological

dragon A dragon is a reptilian legendary creature that appears in the folklore of many cultures worldwide. Beliefs about dragons vary considerably through regions, but dragons in western cultures since the High Middle Ages have often been depicted a ...

s. In the early and mid 20th century, there was controversy about their gliding capabilities, with some authors suggesting that the patagia were solely for display, but research in the late 1950s firmly established the gliding function of the patagia.

Gliding

The lizards are well known for their "display structures" and ability to glide long distances using their wing-like, patagial membranes supported by elongated thoracic ribs to generate lift forces. The hindlimbs in cross section form a streamlined and contoured

airfoil An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbin ...

, and are also probably involved in generating lift. Gliding is both used to escape predators, and as the primary means of moving through their forest habitat. The folding and unfolding of the membrane is controlled by the

iliocostalis Iliocostalis muscle is the muscle immediately lateral to the longissimus that is the nearest to the furrow that separates the epaxial muscles from the hypaxial. It lies very deep to the fleshy portion of the serratus posterior muscle. It latera ...

and

intercostal muscles Intercostal muscles are many different groups of muscles that run between the ribs, and help form and move the chest wall. The intercostal muscles are mainly involved in the mechanical aspect of breathing by helping expand and shrink the size of ...

, that in other lizards are used to control breathing. At takeoff, the lizard jumps and descends headfirst, orientating itself so that the underside of the body is parallel to the ground. During flight, the back arches, forming the patagium into a cambered surface, and the forelimbs grab the front of the patagium, forming a straight front edge to the aerofoil. The forelimbs are used to manipulate the patagium in order to adjust the trajectory during flight. Maximum gliding speeds have been found to be between 5.2 and 7.6 metres per second, depending on the species. During the landing process, the glide is mostly horizontal. Immediately before landing, the forelimbs release the patagium. The landing is forefeet-first, followed by hindfeet. The shape of the gliding membrane does not correlate with body size, meaning the larger species have proportionately less lift-generating surface area and consequently higher

wing loading In aerodynamics, wing loading is the total mass of an aircraft or flying animal divided by the area of its wing. The stalling speed of an aircraft in straight, level flight is partly determined by its wing loading. An aircraft or animal with a ...

Habitat and ecology

Members of ''Draco'' are primarily

, inhabiting tropical rainforests, and are almost never found on the forest floor. They are

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were ...

, primarily feeding on

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

s and

termite Termites are small insects that live in colonies and have distinct castes ( eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blat ...

s. The colour of the patagium is strongly correlated to the colour of the local falling leaves, likely as camouflage against predatory birds.

Social behaviour and reproduction

''Draco'' lizards are highly territorial, with the home range consisting of one or a few trees. The trees are actively guarded by males, with territory-less males searching the forest landscape in search of vacant areas. Experimental studies have determined that suitable unoccupied territories were claimed within a few hours of the removal of a dominant male. Females move freely through the territories. The patagium is used as a display structure during courtship and territorial disputes between rival males, alongside the opening of a colourful

dewlap A dewlap is a longitudinal flap of skin or similar flesh that hangs beneath the lower jaw or neck of many vertebrates. More loosely, it can be various similar structures in the neck area, such as those caused by a double chin or the submandibul ...

. The dewlap is translucent, and deliberately orientated perpendicular to the orientation of the sun during display in order to enhance visibility. ''Draco'' is

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, with females being larger than males. The only time a female flying lizard ventures to the ground is when she is ready to lay her

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 ...

. She descends the tree she is on and makes a nest hole by forcing her head into the soil. She then lays 2–5 eggs before filling the hole and guards the eggs for approximately 24 hours, but then leaves and has nothing more to do with her offspring.

Distribution

Species of ''Draco'' are widely distributed in the forests of Southeast Asia, and one species, '' Draco dussumieri,'' inhabits

Southern India South India, also known as Dakshina Bharata or Peninsular India, consists of the peninsular southern part of India. It encompasses the Indian states of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, and Telangana, as well as the union territ ...

Phylogenetics

Within

Agamidae Agamidae is a family (biology), family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview phylogenetics, Phylogenetic ...

, ''Draco'' is a member of the subfamily Draconinae. Within Draconinae, ''Draco'' is most closely related to the genera ''

Japalura ''Japalura'' is a genus of lizards in the family Agamidae. Species of ''Japalura'' are native to Pakistan, India, China, and Myanmar. Many species have been moved to the genus '' Diploderma''. Species The following eight species are recognized ...

'' and '' Ptyctolaemus.''

Species

The following 40

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 appropriat ...

are recognized: * '' Draco abbreviatus'' – Singapore flying dragon * '' Draco beccarii'' Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Draco beccarii'', p. 21). * '' Draco biaro'' – Lazell's flying dragon * '' Draco bimaculatus'' – two-spotted flying lizard * '' Draco blanfordii'' – Blanford's flying dragon, Blandford’s flying lizard, Blanford's gliding lizard * '' Draco boschmai'' * '' Draco caerulhians'' * '' Draco cornutus'' * '' Draco cristatellus'' – crested flying dragon * '' Draco cyanopterus'' * '' Draco dussumieri'' – Indian flying lizard, Western Ghats flying lizard, southern flying lizard * '' Draco fimbriatus'' – fringed flying dragon, crested gliding lizard * '' Draco formosus'' – dusky gliding lizard * '' Draco guentheri'' – Günther's flying lizard, Guenther's flying lizard * '' Draco haematopogon'' – red-bearded flying dragon, yellow-bearded gliding lizard * '' Draco indochinensis'' – Indochinese flying lizard, Indochinese gliding lizard * '' Draco iskandari'' * '' Draco jareckii'' * '' Draco lineatus'' – lined flying dragon * '' Draco maculatus'' – spotted flying dragon * '' Draco maximus'' – great flying dragon, giant gliding lizard * '' Draco melanopogon'' – black-bearded gliding lizard, black-barbed flying dragon * '' Draco mindanensis'' – Mindanao flying dragon, Mindanao flying lizard * '' Draco modiglianii'' – lined flying dragon * '' Draco norvillii'' – Norvill's flying lizard * '' Draco obscurus'' – dusky gliding lizard * ''

Draco ornatus ''Draco ornatus'', the white-spotted flying lizard, is a species of Agamidae, agamid lizard. It is found in the Philippines. References

Draco (genus) Reptiles of the Philippines Reptiles described in 1845 Taxa named by John Edward Gray ...

'' – white-spotted flying lizard * '' Draco palawanensis'' * '' Draco quadrasi'' – Quadras's flying lizard * '' Draco quinquefasciatus'' – five-lined flying dragon, five-banded gliding lizard * '' Draco reticulatus'' * '' Draco rhytisma'' * ''

Draco spilonotus ''Draco spilonotus'', the Sulawesi lined gliding lizard, is a lizard endemic to Sulawesi. The species is known from various localities in forested areas of Sulawesi. The patagium of the male is yellow in colour and has a network of brown lines r ...

'' – Sulawesi lined gliding lizard * '' Draco spilopterus'' – Philippine flying dragon * '' Draco sumatranus'' – common gliding lizard * '' Draco supriatnai'' * ''

Draco taeniopterus ''Draco taeniopterus'', the Thai flying dragon, barred flying dragon, or barred gliding lizard, is a species of Agamidae, agamid lizard. It is found in Myanmar, Thailand, Cambodia, and Malaysia. References

Draco (genus) Reptiles of Myanm ...

'' – Thai flying dragon, barred flying dragon, barred gliding lizard * '' Draco timoriensis'' – Timor flying dragon * ''

'' – common flying dragon * '' Draco walkeri'' ''

Nota bene (, or ; plural form ) is a Latin phrase meaning "note well". It is often abbreviated as NB, n.b., or with the ligature and first appeared in English writing . In Modern English, it is used, particularly in legal papers, to draw the atte ...

'': a binomial authority in parentheses indicates that the species was originally described in a genus other than ''Draco''.

Prehistoric analogues

Several other lineages of reptile known from the fossil record have

convergently evolved Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

similar gliding mechanisms, the oldest of these being the weigeltisaurids, known from the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

, around 258 to 252 million years ago. Other lineages include the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

kuehneosaurids and '' Mecistotrachelos,'' and the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

lizard '' Xianglong''.