Gonocephalus are a medium-sized genus of distinctive-looking agamids distinguished by their cranial shape, which gives them the scientific and common name of "angleheads". A few have become established in captivity, although breeding remains sporadic. They are egg-layers. As with other agamids, there is a certain colour-changing ability in these lizards which owes mainly to mood rather than a desire to camouflage. Most if not all live in forested areas at 0-1,600m (0-4,800ft) in altitude, where the majority are found fairly high up in the trees, either clinging to vertical tree trunks or sitting on the end of thin branches. Running water in the form of a stream or similar is never usually far away.
Among characteristics of the genus are the following: body laterally flattened: throat and shoulder fold, gular pouch, nape crest and visible tympanum always present in both sexes: dorsal scales either small and homogoneous or mixed with larger ones: head rather triangular: tail strong, does not regenerate if broken.
These are fairly spectacular lizards, but by no means easy to provide for in terms of accommodation. Manthey and Schuster recommend an average terrarium size of no less than 150 x 150 x 70 cm (about 5 x 5 x 2½ft), planted with sturdy plants with both thick and thin branches. The basic model for keeping these species is either the rain-forest or cloud-forest terrarium: the latter requires humidity but not excessively high temperatures. There is not much in print (at least outside academic publications) dedicated to these lizards, and species identification can be difficult. It should however be noted that DeVosjoli recommends these lizards for specialists rather than beginners.
Please note that as we obtain more precise data for these lizards, we will try to keep this page updated, if only because these and similar agamids (often going under the names of "tree dragon" or "mountain dragon") appear from time to time in the pet trade but often with very little available information on them.
|G. belli||G. beyschlagii||G. borneensis|
|G. chamaeleontinus||G. denzeri||G. doriae|
|G. grandis||G. interruptus, Mindoro Anglehead||G. klossi|
|G. kuhli||G. lacunosus||G. liogaster|
|G. megalepis||G. mjoebergi||G. robinsonii|
|G. semperi, White-Spotted Anglehead||G. sophiae, Dark-Spotted Anglehead|
|Scientific Name||Common Name||Distribution||Size||Notes|
|G. belli||Thailand, Indonesia (Borneo), West Malaysia||9-13"||This species lives on thick tree trunks near flowing water at altitudes between sea level and 1,000m (3,000ft). Manthey and Schuster say that it can be kept with other Gonocephalus species (except for G. grandis) or the Acanthosaurus "prickle-napes" agamids.|
|G. beyschlagi||Indonesia (N Sumatra)||?"|
|G. borneensis||South Australia and Victoria: possibly New South Wales||8-12"||Found in the vicinity of flowing water on thick tree trunks or lianas. Unusually for this genus, fleeing individuals seek hiding places on the ground rather than heading up into the canopy.|
|G. chamaeleontinus||Indonesia, W Malaysia||12"||?.|
|G. doriae||S Thailand, W Malaysia, Sarawak and Indonesia||5-9"||Manthey and Schuster recommend this as a peaceful species which should be kept in a lowland rainforest terrarium.|
|G. d. doriae||Sarawak and Indonesia (Kalimantan)||5-7½"|
|G. d. abbotti||S Thailand and W Malaysia||8-9"|
|G. grandis||Thailand, W Malaysia,
Indonesia (Sumatra, Nias, Mantawes & Borneo)
|12-17"||This is apparently the most aggressive species of the genus, and should therefore be kept in single pairs of one male, one female. In nature they live in trees and bushes directly alongside flowing water: juveniles and females may also be found by or in the water itself.|
|G. interruptus||Mindoro Anglehead||Philippines (Mindoro)||7½"||Found in tropical rain forest at about 1,000m altitude. Its crest is lower than those of G. semperi and G. sophiae. Coloration (preserved specimens): black-reddish brown with 5 thin light transverse bars across the back. Tail has alternating transverse bands. Ventrally mottled brown. Reproduction: no details available. [SOURCE: Alcala]|
|G. klossi||Indonesia (W Sumatra)||?"|
|G. kuhli||Indonesia (Java and Sumatra)||6-7½"||Resembles G. chamaeleontinus. Found mainly at higher altitudes up to 1,600m (4,800ft) but also in lowland.|
|G. lacunosus||Indonesia (N Sumatra)||8-11"||Found in montane forest above 1,000m (3,000ft), usually near streams. It sits on thin trees or on the ground and hides in holes. Manthey and Schuster suggest a cloud-forest terrarium. Apparently it is a quiet and withdrawn terrarium subject.|
|G. liogaster||W Malaysia and Indonesia (Sumatra, Borneo and Natuna Islands)||9-13"||Found in jungles on tree trunks not far from water. The species is distinguished by a taill continuous crest of narrow scales. Coloration: overall brown but with dark bands around the feet and tail: dewlap is black or has black spots.|
|G. megalepis||Indonesia (Sumatra and Borneo)||?"|
|G. robinsonii||W Malaysia||11-13"||Found in montane forest at 1,000m and above near flowing water, on thin trees and also among ferns along paths. The sexes can be hard to distinguish. Manthey and Schuster suggest the cloud-forest terrarium.|
|G. semperi||Light-Spotted Anglehead||Philippines (Negros, Mindanao, Panay)||9-11½ cm SVL||Found in tropical rain forests from sea level to 1,000m, on trees and shrubs and beneath rotting logs. Scalation: dorsal and lateral scales generally smaller than ventrals, which are more strongly keeled. Several roughly vertical rows of enlarged spiny scales on body, plus a row of the same running parallel to, but several rows distance from, the crest. 5-7 rows of small scales between rows of greatly enlarged scales above the eyes. 106-130 rows at midbody. There is a gap between the the dorsal and nuchal crests. Coloration (preserved specimens): overall grey-brown or pale red-brown to light or dark brown, with either blotches or a mesh of slate, dark brown or black. Enlarged dorsal and lateral scales are often paler, to whitish. Ventrally lighter, usually more "dusky" (Alcala) or with dark bars or spots under head and neck. The tail has alternating dark transverse bands. Reproduction: no details available. [SOURCE: Alcala]|
|G. sophiae||Dark-Spotted Anglehead||Philippines (Mindoro and Mindanao)||8-11½ cm SVL||Found in tropical rainforest from sea level to 600m. Scalation: similar to G. semperi but with only a few scattered, enlarged spiny scales. 4-6 (usually 5) eye scales. 128-142 rows at midbody. The dorsal and nuchal crest are continuous, high all the way in males but lower, especially on the back, for females. Coloration (preserved specimens): light- to greyish-brown, either uniformly or with very variable dark brown blotches or mesh on the body and many round or elongated dark spots on the base of the tail and limbs. Ventral surfaces light brown, throat may be dark brown. Reproduction: no details available. [SOURCE: Alcala]|
Crested Dragon has put up a fairly helpful site that gives a little information on and very helpful pictures of both Gonocephalus and the similar-looking Hypsilurus species. Worth a visit.
www.kingsnake.com have a forum devoted to Gonocephalus and close friends, under the name of Mountain and Tree Dragon forum.
www.ecologyasia.com has a nice short page on G. borneensis.
www.herpetobuch.de has some info in German on G. denzeri, grandis, robinsonii and sophiae.