Actinopus

Actinopus is a genus of mygalomorph spiders in the family Actinopodidae. These spiders are commonly known as trapdoor spiders. Actinopus species are found in South America, specifically in Argentina, Brazil, Chile, Paraguay, and Uruguay. They are characterized by their distinctive kidney-shaped rastellum, a structure of spines or teeth located on the chelicerae (jaws) which they use to dig their burrows.

Actinopus spiders construct burrows in the ground which are typically closed with a hinged trapdoor made of soil, vegetation, and silk. This trapdoor conceals the entrance and allows the spider to ambush unsuspecting prey. The spiders are generally nocturnal and spend most of their lives within these burrows.

The genus Actinopus contains numerous species, with ongoing research leading to new discoveries and revisions in classification. Identifying species within this genus can be challenging, requiring careful examination of morphological characteristics.

Due to their reclusive nature and dependence on specific environmental conditions, habitat loss and degradation pose a significant threat to some Actinopus species. Conservation efforts are often hampered by a lack of comprehensive data on their distribution and population sizes.