The Varanthus acanthurus, commonly known as the Ridge-tailed Monitor, is a small, agile lizard native to Australia's arid regions. It features a distinctive spiny tail, used for defense and balance. This species is diurnal, actively hunting insects and small vertebrates. Its adaptability and keen senses make it a proficient predator.

Varanus acanthurus, commonly known as the Spiny-tailed Monitor, is native to Australia. Its geographical distribution includes the northern and central regions of the continent, specifically within the states of Western Australia, Northern Territory, and Queensland.

The Spiny-tailed Monitor inhabits arid and semi-arid environments, characterized by hot and dry climatic conditions. These areas typically experience high temperatures with low annual rainfall. The terrain is often rocky with sparse vegetation, including shrubs and grasses.

This species is well-adapted to life in rocky outcrops, escarpments, and spinifex grasslands. These environments provide shelter and protection from predators, as well as opportunities for basking. The Spiny-tailed Monitor has adapted to these harsh conditions by utilizing crevices and burrows to escape extreme temperatures and to hunt for insects, small mammals, and other reptiles.