Fan-throated Lizard Sitana ponticeriana from Agaminae

Agamids, lizards of the family Agamidae, include more than 300 species in Africa, Asia, Australia, and a few in Southern Europe. They are commonly called dragons or dragon lizards. Phylogenetically they may be sister to the Iguanidae, and have a similar appearance. Agamids usually have well-developed, strong legs. Their tails cannot be shed and regenerated like those of geckoes, though a certain amount of regeneration is observed in some.^[1][2] Many agamid species are capable of limited change of their colours to regulate their body temperature.^[3] In some species, males are more brightly coloured than females^[4] and colours play a part in signaling and reproductive behaviours.^[5] Although agamids generally inhabit warm environments, ranging from hot deserts to tropical rainforests, at least one species, the Mountain Dragon, is found in cooler regions.

One of the key distinguishing features of the agamids is their teeth, which are borne on the outer rim of the mouth (acrodont), rather than on the inner side of the jaws (pleurodont). This feature is shared with the chameleons, but is otherwise unusual among lizards. Agamid lizards are generally diurnal, with good vision, and include a number of arboreal species, in addition to ground and rock-dwellers. They generally feed on insects and other arthropods (such as spiders), although some larger species may include small reptiles or mammals, nestling birds, flowers or other vegetable matter in their diets.^[6] The great majority of agamid species are oviparous.^[7]

Systematics and distribution

There have been very few studies of the Agamidae with the first comprehensive assessment by Moody (1980) followed by a more inclusive assessment by Frost and Etheridge (1989). Subsequent studies were based on mitochondrial DNA loci^[8][9][10] (using allozymes), and sampling across the Agamidae. Few other studies focused on clades within the family, but the Agamidae have not been as well investigated as the Iguanidae.

The Agamids show a curious distribution. They are found over much of the Old World, including continental Africa, Australia, Southern Asia and sparsely in warmer regions of Europe. They are however absent from Madagascar and from the New World. The distribution is the opposite of that of the Iguanids, who are found in just these areas but absent in areas where Agamids are found. A similar faunal divide is found in between the Boas and Pythons.

Subfamilies^[11]

Among the Agamidae, six clades or lineages are generally recognized^{[citation needed]}:

• Agaminae (African and Australian)
• Amphibolurinae (Australian and New Guinean)
• Draconinae (South and Southeast Asian)
• Hydrosaurinae (Hydrosaurus)
• Leiolepidinae (Leiolepis)
• Uromasticinae (Saara and Uromastyx)

The chameleons of the sister family Chamaeleonidae are sometimes discussed^{[citation needed]} as subfamily Chamaeleoninae and subfamily Agaminae (referring to Agamidae, not the Agaminae mentioned above).

References

Wikimedia Commons has media related to: Agamidae

Wikispecies has information related to: Agamidae

Boyd's Forest Dragon (Hypsilurus boydii or Gonocephalus boydii) is restricted to the rainforests of northern Queensland, Australia, from just north of Townsville to near Cooktown. It is found in both upland and lowland rainforest, and is often seen around Lake Eacham (Yidyam) and Lake Barrine, and can also be seen in parts of Malanda Falls Environmental Park and at Mossman Gorge.

It has very enlarged cheek scales, a prominent crest, and a yellow dewlap under its chin. Adults are sexually dimorphic, with males larger than females and having larger, blockier heads.

It spends the majority of its time perched on the trunks of trees, usually at around head height, although daily movements can exceed 100 metres. When approached, it will usually move around to the opposite side of the tree, keeping the trunk between it and its harasser. It doesn't bask, instead letting its body temperature fluctuate with air temperature. The one possible exception to this general rule is gravid females, which are often observed sitting beside roads and exhibit elevated body temperatures. Lizards commence activity at dawn and cease activity at dusk, remaining active even when it rains. Activity is highly seasonal, all but ceasing during the cooler months, when lizards move into the rainforest canopy.

Both males and females appear to be territorial, with males defending an area of around 1,000 square metres. Female territories are smaller, with male territories often containing the territories of more than one female.

Diet consists primarily of invertebrates, with earthworms making up a relatively high proportion. Small fruits and vertebrates are also occasionally consumed.

Reproduction is via eggs, with clutch sizes varying from one to six eggs. Females in lowland populations may lay more than one clutch in a season. The eggs are laid in shallow nests, often in rainforest clearings - both natural and man-made (the verges of roads are particularly popular). Sexual maturity is achieved in around one to two years in lowland populations but probably takes at least a year longer in upland populations.

References

• Boyd's Forest Dragon

This Australia-related article is a stub. You can help Wikipedia by expanding it. v t e

Wikimedia Commons has media related to: Hypsilurus boydii