Desert-dwelling animals are called:

1. A

   Arboreal animals

   Arboreal animals are those that live in trees, such as monkeys and squirrels. This term describes canopy-dwelling species rather than organisms adapted to arid desert biomes. Therefore, option (a) is incorrect.

2. B

   Terrestrial animals

   Terrestrial animals are land-dwelling organisms that walk, run, or burrow on the ground. While desert animals live on land, terrestrial is too broad and does not specify the extreme arid adaptation meant here. Thus, option (b) is incorrect.

3. C

   Fossorial animals

   Fossorial animals are adapted for digging and spending a significant portion of their lives underground, like moles and certain rodents. Although many desert dwellers burrow, this term specifically highlights subterranean habits rather than overall desert adaptations. Hence, option (c) is incorrect.

4. D

   Xericoles animals

   Xericoles animals are specifically defined as organisms that inhabit dry or desert environments and have evolved physiological and behavioral adaptations to survive extreme water scarcity and high temperatures. This precise ecological term directly answers the question regarding desert-dwelling species, making it the correct choice. Consequently, option (d) is the official key.

Summary. Official key is (d) Xericoles animals. The question asks for the specific biological term used to describe organisms that inhabit desert ecosystems. While terms like terrestrial and fossorial describe general land or burrowing habits, they lack the specific focus on arid adaptations. Arboreal refers strictly to tree-dwelling creatures found in forests. Only xericoles accurately captures the specialized nature of desert-dwelling fauna.