''Draco'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of agamid

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

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 flying and gliding animals, gliding animals and by aircraft such as glider (aircraft), gl ...

via membranes that may be extended to create wings (

patagia The patagium (: patagia) is a membranous body part that assists an animal in obtaining lift when gliding or flying. The structure is found in extant and extinct groups of flying and gliding animals including bats, theropod dinosaurs (includin ...

), formed by a support structure from 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 (scansorial), but others are exclusively arboreal. The hab ...

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

. 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 makes for a

glide ratio In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under give ...

of 6:1. This is done by a lizard of 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) was an educational and academic publisher (middle school through university level) which was part of ABC-Clio. Since 2021, ABC-Clio and its suite of imprints, including GPG, are collectively imprints of B ...

. They are found across Southeast Asia and Southern India and are fairly common in

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

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

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 (panic ...

plantations and

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

jungle.

History of discovery

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

described the genus in 1758, with the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

being '' Draco volans.'' 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 spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

term for

dragon A dragon is a Magic (supernatural), magical legendary creature that appears in the folklore of multiple cultures worldwide. Beliefs about dragons vary considerably through regions, but European dragon, dragons in Western cultures since the Hi ...

s of

mythology Myth is a genre of folklore consisting primarily of narratives that play a fundamental role in a society. For scholars, this is very different from the vernacular usage of the term "myth" that refers to a belief that is not true. Instead, the ...

. In the early and mid 20th century, there was controversy about their gliding capabilities, with some authors suggesting that the

were solely for display, but research in the late 1950s firmly established the gliding function of the patagia.

Distribution and habitats

Species of ''Draco'' are widely distributed in the forests of

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

, with one species, '' Draco dussumieri,'' inhabiting

Southern India South India, also known as Southern India or Peninsular India, is the southern part of the Deccan Peninsula in India encompassing the states of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and Telangana as well as the union territories of ...

. Members of ''Draco'' are primarily

, inhabiting tropical rainforests, and are almost never found on the

forest floor The forest floor, also called detritus or wikt:duff#Noun 2, duff, is the part of a forest ecosystem that mediates between the living, aboveground portion of the forest and the mineral soil, principally composed of dead and decaying plant matter ...

Overall description

They are

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

, primarily feeding on eusocial insects such as

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

s and

termite Termites are a group of detritivore, detritophagous Eusociality, eusocial cockroaches which consume a variety of Detritus, decaying plant material, generally in the form of wood, Plant litter, leaf litter, and Humus, soil humus. They are dist ...

s. The colour of the patagium is strongly correlated to the colour of falling leaves in their range, which complements their cryptic camouflage resembling

tree bark Bark is the outermost layer of stems and roots of woody plants. Plants with bark include trees, woody vines, and shrubs. Bark refers to all the tissues outside the vascular cambium and is a nontechnical term. It overlays the wood and consist ...

; both are likely to be

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

against predatory birds.

Gliding

The lizards are well known for their "display structures" and ability to glide long distances using their

wing A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-d ...

-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 a streamlined body that is capable of generating significantly more Lift (force), lift than Drag (physics), drag. Wings, sails and propeller blades are examples of airfoils. Foil (fl ...

, and are also probably involved in generating lift.

Gliding Gliding is a recreational activity and competitive air sports, air sport in which pilots fly glider aircraft, unpowered aircraft known as Glider (sailplane), gliders or sailplanes using naturally occurring currents of rising air in the atmospher ...

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 late ...

and

intercostal muscles The intercostal muscles comprise 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 th ...

, which 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 A trajectory or flight path is the path that an object with mass in motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates; hence, a complete tra ...

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. Draco takeoff.gif, Takeoff and initial stages of gliding, slowed down 10x, showing the attachment of the forelimbs to the gliding membrane Draco landing.gif, Landing, slowed down 20x 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 weight of an aircraft or flying animal divided by the area of its wing. The stalling speed, takeoff speed and landing speed of an aircraft are partly determined by its wing loading. The faster an airc ...

Life history

''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 brightly-colored

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 submandibula ...

that contrasts with their camouflaged body scalation. The dewlap is translucent, and deliberately orientated

perpendicular In geometry, two geometric objects are perpendicular if they intersect at right angles, i.e. at an angle of 90 degrees or π/2 radians. The condition of perpendicularity may be represented graphically using the '' perpendicular symbol'', � ...

to the orientation of the

sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

during display in order to enhance visibility. ''Draco'' lizards are

sexually dimorphic Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, 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. She descends the tree she is on and makes a nest hole by forcing her head into the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

. She then lays a

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

of 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.

Phylogenetics

Within

Agamidae Agamidae is a family containing 582 species in 64 genera of iguanian lizards indigenous to Africa, Asia, Australia, and a few locations in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview Phylogenetically ...

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

Species

The following 41

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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, Blanford’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'' – white-spotted flying lizard * '' Draco palawanensis'' * '' Draco punctatus'' – punctate flying dragon * '' 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 The patagium (: patagia) is a membranous body part that assist ...

'' – Sulawesi lined gliding lizard * '' Draco spilopterus'' – Philippine flying dragon * '' Draco sumatranus'' – common gliding lizard * '' Draco supriatnai'' * '' Draco taeniopterus'' – Thai flying dragon, barred flying dragon, barred gliding lizard * '' Draco timoriensis'' – Timor flying dragon * '' Draco volans'' – common flying dragon * '' Draco walkeri'' ''

Nota bene ( ; plural: ) is the Latin language, Latin phrase meaning ''note well''. In manuscripts, ''nota bene'' is abbreviated in upper-case as NB and N.B., and in lower-case as n.b. and nb; the editorial usages of ''nota bene'' and ''notate bene'' fi ...

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

Similar prehistoric reptiles

Several other lineages of reptile known from the

fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

have convergently evolved similar gliding mechanisms consisting of a patagium or plate flanking the torso; the weigeltisaurids are the oldest of these, living in the

Late Permian Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudonym used by Dave Groh ...

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

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

kuehneosaurids and ''

Mecistotrachelos ''Mecistotrachelos'' is an extinction, extinct genus of gliding reptile from the Late Triassic of Virginia. It is generally interpreted as an Archosauromorpha, archosauromorph, distantly related to Crocodilia, crocodylians and dinosaurs. The type ...

,'' and the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

lizard '' Xianglong''.