Order PSEUDOSCORPIONES

Museums

Regional Maps

Introduction

Pseudoscorpiones, the arachnid order commonly known as pseudoscorpions or false scorpions, are a small but significant group of predators that occupies virtually every terrestrial habitat. They even colonise such inhospitable places as the intertidal zone of the seashore, and live as commensals inside the nests of social insects. Pseudoscorpions attract little attention outside scientific circles because of their small size, inoffensive nature and secretive habits, but several are known to be synanthropic (Weygoldt 1969). Their role in the food cycle is probably quite significant since they are often found in high densities, especially in leaf litter. For example, Gabbutt (1967) recorded Chthonius ischnocheles (Hermann), Roncus lubricus L. Koch and Neobisium muscorum (Leach) in densities of up to 900 per square metre in beech leaf litter. An excellent account of the morphology and general biology of the pseudoscorpions is given by Chamberlin (1931), and a further account of their biology is given by Weygoldt (1969).

Pseudoscorpions are one of the few terrestrial groups of living organisms for which the ancestry can be traced back to the Devonian. Dracochela deprehendor Schawaller et al., described from the middle Devonian, displays features that are hypothesised to be unable to occur in aquatic habitats (Schawaller et al. 1991).

Over 3200 pseudoscorpion species are recognised worldwide (Harvey 1991, and unpublished data). Only 150 species are described currently in the Australian fauna, but studies are still in their infancy, with many more species in museum collections awaiting description. The Australian fauna was catalogued by Harvey (1981, 1985), but numerous new taxa have been recorded since those lists, and the total Australian fauna may eventually number over 700.

CLASSIFICATION

The familial classification adopted in this database follows that proposed by Harvey (1992) which was largely derived and modified from earlier classifications such as those of Chamberlin (1931), Beier (1932a, 1932b) and Muchmore (1982). Harvey (1992) divided the Pseudoscorpiones into two suborders, the Epiocheirata for the Chthonioidea and Feaelloidea, and the Iocheirata for the remaining four superfamilies. He also made a number of changes at the family and superfamily level and produced the first detailed phylogenetic analysis of the group.

The classification has been rearranged to follow the findings of the molecular phylogenetic study by Murienne et al. (2008).

Acknowledgements

I wish to thank the many museum curators for placing type material at my disposal or for assisting in ascertaining the status of material in their care.

Database Notes

The information on the Australian Faunal Directory site for the Pseudoscorpiones is derived from the Zoological Catalogue of Australia database compiled on the Platypus software program. The original work was published on 9 September 1985 in the Zoological Catalogue of Australia Vol. 3. The database was updated in 2012.

Limital Area

Distribution data in the Directory is by political and geographic region descriptors and serves as a guide to the distribution of a taxon. For details of a taxon's distribution, the reader should consult the cited references (if any) at genus and species levels.

Australia is defined as including Lord Howe Is., Norfolk Is., Cocos (Keeling) Ils, Christmas Is., Ashmore and Cartier Ils, Macquarie Is., Australian Antarctic Territory, Heard and McDonald Ils, and the waters associated with these land areas of Australian political responsibility. Political areas include the adjacent waters.

Terrestrial geographical terms are based on the drainage systems of continental Australia, while marine terms are self explanatory except as follows: the boundary between the coastal and oceanic zones is the 200 m contour; the Arafura Sea extends from Cape York to 124 DEG E; and the boundary between the Tasman and Coral Seas is considered to be the latitude of Fraser Island, also regarded as the southern terminus of the Great Barrier Reef.

Distribution records, if any, outside of these areas are listed as extralimital. The distribution descriptors for each species are collated to genus level. Users are advised that extralimital distribution for some taxa may not be complete.

 

Excluded Taxa

Misidentifications

SYARINIDAE: Ideobisium antipodum (Simon, 1880) — Harvey, M.S. 1981. A checklist of the Australian Pseudoscorpionida. Bulletin of the British Arachnological Society 5: 237-252 [238]

 

Diagnosis

Pseudoscorpions differ from all other arachnids, apart from scorpions, in having the pedipalps chelate, such that the pedipalpal tibia and tarsus form a grasping appendage. They differ from scorpions in lacking an elongate metasomal tail and associated sting.

 

General References

Beier, M. 1932a. Pseudoscorpionidea I. Suborder Chthoniinea et Neobisiinea. Das Tierreich 57: i-xx 1-258

Beier, M. 1932b. Pseudoscorpionidea II. Suborder Cheliferinea. Das Tierreich 58: i-xxi, 1-294

Chamberlin, J.C. 1931. The arachnid order Chelonethida. Stanford University Publications, Biological Sciences 7: 1-284

Gabbutt, P.D. 1967. Quantitative sampling of the pseudoscorpion Chthonius ischnocheles from beech litter. Journal of Zoology, London 151: 469-478

Harvey, M.S. 1981. A checklist of the Australian Pseudoscorpionida. Bulletin of the British Arachnological Society 5: 237-252

Harvey, M.S. 1985. Pseudoscorpionida. pp. 126-155 in Walton, D.W. (ed.). Zoological Catalogue of Australia. Volume 3. Arachnida: Mygalomorphae, Araneomorphae (in part), Pseudoscorpionida, Amblypygi and Plapigradi. Canberra : Australian Government Publishing Service x 183 pp.

Harvey, M.S. 1991. Catalogue of the Pseudoscorpionida. Manchester : Manchester University Press.

Harvey, M.S. 1992. The phylogeny and classification of the Pseudoscorpionida (Chelicerata: Arachnida). Invertebrate Taxonomy 6: 1373-1435

Muchmore, W.B. 1982. Pseudoscorpionida. pp. 96-102 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw-Hill Vol. 2.

Murienne, J., Harvey, M.S. & Giribet, G. 2008. First molecular phylogeny of the major clades of Pseudoscorpiones (Arthropoda: Chelicerata). Molecular Phylogenetics and Evolution 49: 170-184

Schawaller, W., Shear, W.A. & Bonamo, P.M. 1991. The first Paleozoic pseudoscorpions (Arachnida, Pseudoscorpionida). American Museum Novitates 3009: 1-24

Weygoldt, P. 1969. The Biology of Pseudoscorpions. Cambridge : Harvard Univ. Press xiv 145 pp.

 

History of changes

Published	As part of group	Action Date	Action Type	Compiler(s)
07-Feb-2024	PSEUDOSCORPIONES	17-Oct-2024	MODIFIED
10-May-2022	PSEUDOSCORPIONES	17-Oct-2024	MODIFIED
18-May-2016	PSEUDOSCORPIONES	17-Oct-2024	MODIFIED	Mark Harvey
24-Dec-2015	PSEUDOSCORPIONES	17-Oct-2024	MODIFIED	Mark Harvey
31-Oct-2012		17-Oct-2024	MODIFIED
		17-Oct-2024	MODIFIED