Cyclocosmia

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Mygalomorphae
Family: Halonoproctidae
Genus: Cyclocosmia

Pronunciation

How to pronounce Cyclocosmia: //ˌsaɪkloʊˈkoʊzmiə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Cyclocosmia sp. in burrow (Marshal Hedin) by Marshal Hedin. Used under a CC BY-SA 2.5 license.

PSM V38 D205 Cyclocosmia truncata by Unknown authorUnknown author. Used under a Public domain license.

Hentz-Mygale-truncata by Nicholas Marcellus Hentz. Used under a Public domain license.

Cyclocosmia truncata by Jason Bond. Used under a CC BY 3.0 license.

PSM V38 D205 Truncata closing her burrow with her abdomen by Unknown authorUnknown author. Used under a Public domain license.

PSM V38 D205 Side view of cyclocosmia truncata by Unknown authorUnknown author. Used under a Public domain license.

Summary

Cyclocosmia is a genus of mygalomorph trapdoor spiders known for their distinct truncated abdomens and the construction of cryptic trapdoor burrows. Described by Anton Ausserer in 1871, they are primarily distributed across the USA and parts of Asia with several recognized species.

Physical Characteristics

Females of Cyclocosmia ricketti are approximately 28 millimetres long, with a disk diameter of 16 millimetres. They have abdomens that are abruptly truncated, ending in a hardened disc strengthened by a system of ribs and grooves. The disks have strong spines around the edge, and each spider has four spinnerets just anterior to the disc.

Identification Tips

Species are distinguished by the pattern of the abdominal disk, the number of hairs on its seam, and the shape of the spermathecae.

Habitat

Cyclocosmia species are found in cryptic habitats, commonly constructing trapdoors for their burrows.

Distribution

Two known US species are found in central Tennessee, Alabama, western Georgia, and northern Florida. Other species are distributed across China, Thailand, Vietnam, Laos, and Mexico.

Diet

As mygalomorph trapdoor spiders, Cyclocosmia likely prey on insects and other small invertebrates that come near their trapdoors.

Ecosystem Role

As predators, Cyclocosmia species play a role in controlling insect populations in their ecosystems.

Evolution

Originally placed within the family Ctenizidae, Cyclocosmia was reassigned to the family Halonoproctidae when it split in 2018, being recognized as the type genus.