Hump-nosed lizard (Lyriocephalus scutatus)

The Hump-nosed lizard, scientifically known as Lyriocephalus scutatus, is a notable agamid species endemic to Sri Lanka and is the largest of its kind found on the island. This lizard is distinguished by a prominent bony hump on the heads of adult individuals, which gives it its common name. It is a resident of the dense, wet zone forests and mid-elevation hills of Sri Lanka, often found in habitats with high canopies and thick undergrowth.

Habitat and Distribution

This species is widespread across the wet lowlands and midhills of Sri Lanka, with recorded elevations ranging from 25 meters up to 1650 meters. It can frequently be observed in areas such as the Pitadeniya region within the Sinharaja World Heritage Site, indicating its presence in protected and biodiverse environments. While primarily a forest dweller, it occasionally ventures into home gardens.

Physical Description

The Hump-nosed lizard possesses a laterally compressed body. Adult males are typically a vibrant green, featuring a bright yellow throat pouch and a noticeable neck sail. Females, on the other hand, are usually brown, particularly when in the presence of a male, although they can also exhibit green coloration. Juveniles are characteristically brown. Anatomical features include a pair of small spines at the back of the head, a developed dorso-nuchal crest, and keeled forehead scales. The absence of a tympanum and the presence of a V-shaped gular sac, along with large, keeled gular scales, are also characteristic. Its tail is short, compressed, and ends in a blunt tip.

Ecology and Behavior

This lizard is diurnal, meaning it is active during the day. Its typical behavior involves dwelling near the ground or on low tree branches. For sleeping, it ascends higher up into trees. When faced with a perceived threat, the Hump-nosed lizard adopts a distinctive posture, gaping its mouth open to reveal a vivid red lining. It is also known for its ability to feign death when captured.

Diet

The diet of the Hump-nosed lizard is varied, primarily consisting of earthworms. It also consumes various arthropods, including termites, butterflies, and moths. In addition to animal prey, it supplements its diet with young shoots and buds from plants.

Reproduction

Reproduction occurs throughout much of the year, with eggs being laid in months such as January, March, May, June, September, October, and December. A clutch typically contains between one and eleven eggs, which measure approximately 12–13 mm by 20–22 mm. The eggs are carefully buried in the soil, sometimes concealed under bushes. The incubation period for these eggs lasts for about 35 days.