Article · Wikipedia archive · Last revised May 26, 2026

Prosomapoda

Prosomapoda is a clade of euchelicerates including the groups Xiphosura and Planaterga, as well as several basal synziphosurid genera. The clade is defined by the lack of exopods of prosomal appendage II-V in the adult instar, where in contrast the exopods of appendage II-V are well-developed in the non-prosomapod euchelicerates Offacolus and Dibasterium.

Last revised
May 26, 2026
Read time
≈ 1 min
Length
222 w
Citations
4
Source
Prosomapoda
Temporal range:
Cryptocellus goodnighti, a ricinuleid arachnid
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Clade: Euchelicerata
Clade: Prosomapoda
Lamsdell, 2013
Groups

Prosomapoda is a clade of euchelicerates including the groups Xiphosura (horseshoe crabs) and Planaterga (a group comprising bunodids, pseudoniscids, chasmataspidids, eurypterids and arachnids), as well as several basal synziphosurid genera.1 The clade is defined by the lack of exopods (outer branches) of prosomal appendage II-V in the adult instar,1 where in contrast the exopods of appendage II-V are well-developed in the non-prosomapod euchelicerates Offacolus and Dibasterium.23

References

References

  1. Lamsdell, James C. (2012-12-18). "Revised systematics of Palaeozoic 'horseshoe crabs' and the myth of monophyletic Xiphosura". Zoological Journal of the Linnean Society. 167 (1): 1–27. doi:10.1111/j.1096-3642.2012.00874.x. ISSN 0024-4082.
  2. Sutton, Mark D.; Briggs, Derek E. G.; Siveter, David J.; Siveter, Derek J.; Orr, Patrick J. (2002-06-22). "The arthropod Offacolus kingi (Chelicerata) from the Silurian of Herefordshire, England: computer based morphological reconstructions and phylogenetic affinities". Proceedings of the Royal Society of London. Series B: Biological Sciences. 269 (1497): 1195–1203. doi:10.1098/rspb.2002.1986. ISSN 0962-8452. PMC 1691018. PMID 12065034.
  3. Briggs, Derek E. G.; Siveter, Derek J.; Siveter, David J.; Sutton, Mark D.; Garwood, Russell J.; Legg, David (2012-09-25). "Silurian horseshoe crab illuminates the evolution of arthropod limbs". Proceedings of the National Academy of Sciences. 109 (39): 15702–15705. Bibcode:2012PNAS..10915702B. doi:10.1073/pnas.1205875109. ISSN 0027-8424. PMC 3465403. PMID 22967511.