Panarthropoda is a proposed animal clade containing the extant phyla Arthropoda, Tardigrada and Onychophora.[1] Extinct panarthropods that do not belong to any of the modern phyla are classified in the paraphyletic taxon Lobopodia, which is sometimes expanded to include tardigrades and onychophorans as well.[2] A close relationship between onychophorans and arthropods is widely agreed upon, but the position of tardigrades is more controversial.[3] Some studies have found tardigrades to be more closely related to nematodes.[4][5] Not all studies support the monophyly of Panarthropoda,[6] but most do, including neuroanatomical,[7] mitogenomic[8] and palaeontological[9][10] studies. Originally, they were considered to be closely related to the annelids, grouped together as the Articulata, but newer studies place them among the Ecdysozoa.

Temporal range: Cambrian - Recent
Velvet worm (2002).jpg
Scientific classification e
Kingdom: Animalia
Superphylum: Ecdysozoa
(unranked): Panarthropoda
Nielsen, 1995

Common characteristics of the Panarthropoda include the presence of legs and claws, a ventral nervous system, and a segmented body.


Velvet worms (Onychophora) Velvet worm.jpg


Water bears (Tardigrada) Echiniscus L.png

Arthropods (Arthropoda) Long nosed weevil edit.jpg

Sialomorpha, a genus of microinvertebrate discovered in Dominican amber in 2019 also belongs to this group, though its exact placement is uncertain.[11]

See alsoEdit


  1. ^ Telford, M. J (27 April 2008). "The evolution of the Ecdysozoa". Philosophical Transactions of the Royal Society B: Biological Sciences. 363 (1496): 1529–1537. doi:10.1098/rstb.2007.2243. PMC 2614232. PMID 18192181.
  2. ^ Ortega-Hernández, Javier (2016). "Making sense of 'lower' and 'upper' stem-group Euarthropoda, with comments on the strict use of the name Arthropoda von Siebold, 1848: Upper and lower stem-Euarthropoda". Biological Reviews. 91 (1): 255–273. doi:10.1111/brv.12168. ISSN 1464-7931. PMID 25528950.
  3. ^ Giribet, Gonzalo; Edgecombe, Gregory D. (2017). "Current Understanding of Ecdysozoa and its Internal Phylogenetic Relationships". Integrative and Comparative Biology. 57 (3): 455–466. doi:10.1093/icb/icx072. ISSN 1557-7023. PMID 28957525.
  4. ^ Laumer, Christopher E.; Fernández, Rosa; Lemer, Sarah; Combosch, David; Kocot, Kevin M.; Riesgo, Ana; Andrade, Sónia C. S.; Sterrer, Wolfgang; Sørensen, Martin V.; Giribet, Gonzalo (2019-07-10). "Revisiting metazoan phylogeny with genomic sampling of all phyla". Proceedings of the Royal Society B: Biological Sciences. 286 (1906): 20190831. doi:10.1098/rspb.2019.0831. PMC 6650721. PMID 31288696.
  5. ^ Smythe, Ashleigh B.; Holovachov, Oleksandr; Kocot, Kevin M. (2019). "Improved phylogenomic sampling of free-living nematodes enhances resolution of higher-level nematode phylogeny". BMC Evolutionary Biology. 19 (1): 121. doi:10.1186/s12862-019-1444-x. ISSN 1471-2148. PMC 6567515. PMID 31195978.
  6. ^ Dunn, C. W.; Hejnol, A.; Matus, D. Q.; Pang, K.; Browne, W. E.; Smith, S. A.; Seaver, E.; Rouse, G. W.; Obst, M.; Edgecombe, G. D.; Sørensen, M. V.; Haddock, S. H. D.; Schmidt-Rhaesa, A.; Okusu, A.; Kristensen, R. M. B.; Wheeler, W. C.; Martindale, M. Q.; Giribet, G. (10 April 2008). "Broad phylogenomic sampling improves resolution of the animal tree of life". Nature. 452 (7188): 745–749. doi:10.1038/nature06614. PMID 18322464. S2CID 4397099.
  7. ^ Persson, Dennis K. (November 2012). "Neuroanatomy of Halobiotus crispae (Eutardigrada: Hypsibiidae): Tardigrade brain structure supports the clade panarthropoda". Journal of Morphology. 273 (11): 1227–1245. doi:10.1002/jmor.20054. PMID 22806919.
  8. ^ Rota-Stabelli, O.; Kayal, E.; Gleeson, D.; Daub, J.; Boore, J.; Telford, M.; Pisani, D.; Blaxter, M.; Lavrov, D. (2010). "Ecdysozoan mitogenomics: evidence for a common origin of the legged invertebrates, the Panarthropoda". Genome Biology and Evolution. 2: 425–440. doi:10.1093/gbe/evq030. PMC 2998192. PMID 20624745.
  9. ^ Smith, Martin R.; Ortega-Hernández, Javier (2014). "Hallucigenia's onychophoran-like claws and the case for Tactopoda" (PDF). Nature. 514 (7522): 363–366. doi:10.1038/nature13576. PMID 25132546. S2CID 205239797.
  10. ^ Ou, Qiang (2012). "Cambrian lobopodians and extant onychophorans provide new insights into early cephalization in Panarthropoda". Nature Communications. 3: 1261. doi:10.1038/ncomms2272. PMC 3535342. PMID 23232391.
  11. ^ Poinar, George; Nelson, Diane R. (2019). "A new microinvertebrate with features of mites and tardigrades in Dominican amber". Invertebrate Biology. 138 (4): e12265. doi:10.1111/ivb.12265. ISSN 1744-7410.