Haptopoda (Pocock 1911) is an extinct arachnid order known exclusively from a few specimens from the Upper Carboniferous of the UK. It is monotypic, i. e., has only one species, Plesiosiro madeleyi Pocock 1911, recently redescribed by Dunlop (1999). Relationships with other arachnids are obscure, but closest relatives may be the Amblypygi, Thelyphonida and Schizomida of the tetrapulmonate clade (Dunlop, 2000).

Names

The order is also called Haptopodida, the ending -ida originated when Petrunkevitch (1955) tried to standardize the endings of the arachnid orders, which is unnecessary and unwarranted according to the ICZN.

Plesiosiro means "close to Siro", which is a genus of cyphophthalmid Opiliones that in overall appearance resembles the reconstructed body plan of the haptopods.

Haptopoda originates from Greek "haptos" (= tangible, subject to the sense of touch) + "pous, podos" (= foot).

Subtaxa included

The haptopods have a single family which has a single genus and a single species:

Plesiosironidae Pocock 1911

Plesiosiro Pocock 1911

Plesiosiro madeleyi Pocock 1911

References

• Dunlop, J. A. 1997. Palaeozoic arachnids and their significance for arachnid phylogeny. Proceedings of the 16th European Colloquium of Arachnology, 65-82.
• Dunlop, J. A. 1999. A redescription of the Carboniferous arachnid Plesiosiro madeleyi Pocock, 1911 (Arachnida: Haptopoda). Transactions of the Royal Society of Edinburgh: Earth Sciences, 90: 29-47.
• Dunlop, 2000. The Carboniferous arachnid Plesiosiro. 19TH EUROPEAN COLLOQUIUM OF ARACHNOLOGY, 17-22 July 2000, University of Aarhus, Denmark.
• Pocock, R.I. 1911. A monograph of the terrestrial Carboniferous Arachnida of Great Britain. Monographs of the Palaeontographical Society,London, 84 pp.

Arachnids