Cyclocosmia is a genus of mygalomorph trapdoor spiders in the family Halonoproctidae, first described by Anton Ausserer in 1871.[4] Originally placed with the Ctenizidae, when the family split in 2018, this genus was placed with the Halonoproctidae as the type genus.[5] The name is derived from the Greek "kyklos" (κυκλος), meaning "circle", and "kosmeo" (κοσμεω), meaning "to adorn".[6]

Cyclocosmia truncata.jpg
Cyclocosmia truncata
Scientific classification e
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Mygalomorphae
Family: Halonoproctidae
Genus: Cyclocosmia
Ausserer, 1871[1]
Type species
C. truncata
(Hentz, 1841)

10, see text



C. ricketti females are 28 millimetres (1.1 in) long, with a disk diameter of 16 millimetres (0.63 in). Their burrows are 7 to 15 centimetres (2.8 to 5.9 in) deep, and only the bottom portion of the burrow is silk lined.[7]

These are trapdoor spiders, whose species are distinguished from each other by the pattern of the abdominal disk, the number of hairs on its seam, and the shape of the spermathecae. They have abdomens that are abruptly truncated, ending in a hardened disc that is strengthened by a system of ribs and grooves. They use this to clog the entrance of their burrows when threatened,[8] a phenomenon called phragmosis. The disks have strong spines around the edge, and they each have four spinnerets just anterior to it. The posterior, retractable spinnerets are particularly large.


As of April 2019 it contains ten species:[1]


  1. ^ a b c "Gen. Cyclocosmia Ausserer, 1871". World Spider Catalog Version 20.0. Natural History Museum Bern. 2019. doi:10.24436/2. Retrieved 2019-05-27.
  2. ^ Gertsch, W. J.; Platnick, N. I. (1975). "A revision of the trapdoor spider genus Cyclocosmia (Araneae, Ctenizidae)". American Museum Novitates (2580): 5.
  3. ^ Simon, E (1903). Histoire naturelle des araignées. p. 887. doi:10.5962/bhl.title.51973.
  4. ^ Ausserer, A. (1871). "Beiträge zur Kenntniss der Arachniden-Familie der Territelariae Thorell (Mygalidae Autor)". Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien. 21: 117–224.
  5. ^ Godwin, R. L.; et al. (2018). "Phylogeny of a cosmopolitan family of morphologically conserved trapdoor spiders (Mygalomorphae, Ctenizidae) using Anchored Hybrid Enrichment, with a description of the family, Halonoproctidae Pocock 1901". Molecular Phylogenetics and Evolution. 126: 307. doi:10.1016/j.ympev.2018.04.008. PMID 29656103. S2CID 4890400.
  6. ^ "Genus Cyclocosmia". BugGuide. Retrieved 2019-05-27.
  7. ^ Murphy, Frances; Murphy, John (2000). "An Introduction to the Spiders of South East Asia". Malaysian Nature Society. Kuala Lumpur.
  8. ^ Zhu, M.S.; Zhang, J.X; Zhang, F. (2006). "Rare spiders of the genus Cyclocosmia (Arachnida: Araneae: Ctenizidae) from tropical and subtropical China" (PDF). The Raffles Bulletin of Zoology. 54 (1): 119–124. Archived from the original (PDF) on 2007-08-11. Retrieved 2007-08-17.

Further readingEdit

  • Schwendinger, Peter J. (2005): Two new Cyclocosmia (Araneae: Ctenizidae) from Thailand. Revue Suisse de Zoologie 112(1): 225-252

External linksEdit