Angular head dragons

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Angular head dragons
Abbott's angular head dragon (Gonocephalus abbotti)

Abbott's angular head dragon ( Gonocephalus abbotti )

Systematics
Order : Scale reptiles (Squamata)
without rank: Toxicofera
without rank: Iguana (Iguania)
Family : Agamas (Agamidae)
Subfamily : Draconinae
Genre : Angular head dragons
Scientific name
Gonocephalus
Kaup , 1825

The angular head agamas ( Gonocephalus ) are a Southeast Asian genus of agamas . They occur on the Malay Peninsula , the great Sunda Islands Sumatra , Borneo and Java , as well as on Mindanao and some smaller islands in the Philippines .

features

Angular headed dragons were named after their angular head shape ( gonocephalus means angular or angular head). Both the bone ridges between the flat top of the head and the sides of the head ( Canthus rostralis ) and the eyebrow arches (supraorbital) are relatively angular . The lizards reach head-torso lengths of 9 to 17 cm, plus a much longer tail that can be a maximum of 43 cm long. Both sexes show a throat pouch and a neck crest, as well as a throat and shoulder fold. All male angular headed dragons and the females of most species have a back crest consisting of spiky scales, the height of which can vary greatly within a species. The back ridge sits on a dorsal fold of skin covered with large scales arranged in regular rows. The head is covered with small, uneven scales. The tympanum is visible. The scales on the back and on the sides of the body are largely homogeneous, occasionally mixed with larger scales that differ in number and location. On the belly side there are larger scales that have the shape of a diamond and overlap like a roof tile.

Way of life

Angular head dragons are found in the flat and mountainous regions of the rainforests and usually stay in the upper canopy areas of giants of the jungle, which are close to the water, so that they are difficult or impossible to observe. During the day they mainly stay on tree trunks or thick more or less vertical branches; they spend the night on the ends of thin branches. They are oviparous . According to various observations, they defecate in the water.

species

Borneo angular head dragon ( Gonocephalus bornensis )
Robinson's Angular Head Dragon ( Gonocephalus robinsonii )

literature

  • Ulrich Manthey, Wolfgang Grossmann: Amphibians & Reptiles of Southeast Asia. Natur und Tier Verlag (1997), ISBN 978-3931587123 , page 177.

Web links

Commons : Gonocephalus  - Collection of images, videos and audio files