Cycloneuralia

Mansonella ozzardi in blood smear, from the Center for Disease Control.

Belongs within: Ecdysozoa.
Contains: Nematomorpha, Kinorhyncha, Priapozoa, Dorylaimia, Enoplia, Desmoscolecida, Monhysterida, Chromadorida, Desmodorida, Araeolaimida, Plectida, Secernentea.

The Cycloneuralia are a clade of worm-like animals in which the brain neuropil forms a ring around the anterior part of the intestinal system. Members include the Nematoda, roundworms, a hyperdiverse group of mostly minute species, though some parasitic forms may reach large sizes. Free-living nematodes have a characteristically eel-like mode of swimming, as the body wall contains longitudinal muscles only and movement is by dorsoventral flexure of these muscles against the outer cuticle and internal hydrostatic pressure. The dorsoventral plane of flexure also means that most nematodes are unusual among animals in characteristically lying on one side during movement (Lorenzen 1986). An early influential classification divided the nematodes between the Secernentea, possessing sensory structures called phasmids, and the Adenophorea, lacking such structures. However, the Secernentea represent a nested clade within the 'Adenophorea', which is no longer recognised as a valid taxon. Instead, molecular analyses strongly support three primarily clades within the nematodes, Dorylaimia, Enoplia and Chromadorea, with the Secernentea a subgroup of the last (Ley & Blaxter 2002).

<==Cycloneuralia [Nematoida] B01
    |--+--Nematomorpha OH17
    |  `--+--Kinorhyncha OH17
    |     `--Priapozoa OH17
    `--Nematoda [Adenophorea, Aphasmidia, Ascaridatina, Nemata, Nematelmia, Nematelminthes, Nemates, Nemathelminthes] OH17
         |  i. s.: Peloderma G01
         |         Caballeronema pseudoargumentosus Mus02
         |         Truttaedacnitis sphaerocephala Mus02
         |         Thynnascaris N02
         |           |--T. aduncum [=Contracaecum aduncum] N02
         |           `--T. habena [=Contracaecum habena] C02a
         |         Hysterothylacium K-M02
         |           |--H. aduncum K-M02
         |           `--H. pelagicum C02b
         |         Contracaecum osculatum Mun02
         |         Spinitectus cristatus K-M02
         |         Benthimermithidae [Benthimermithida] LB02
         |         Rhaptothyreidae [Rhaptothyreida] LB02
         |         Mazamastrongylus odocoilei LB02
         |         Placentonema gigantissimum Gubanov 1951 L86
         |         Histiocephalus bucorvi Gi02
         |         Tanqua tiara Gi02
         |         Cylicodontostomum purvisi Gi02
         |         Agriostomum Gi02
         |         Allodapa suctoria Gi02
         |         Stegophorus Gi02
         |         Striatofilaria Gi02
         |         Setaria digitata B02
         |         Cyathospirura seurati Gi02
         |         Ternidens deminutus Gi02
         |         Streptopharagus pigmentatus Gi02
         |         Gyalocephalus capitatus Gi02
         |         Bunostomum Railliet 1902 C92
         |           `--B. trigonocephalum MM02
         |         Hexametra Gi02
         |         Hyostrongylus rubidus Gi02
         |         Parostertagia heterospiculum Gi02
         |         Ashworthius pattoni Gi02
         |         Hoplodontophorus flagellum Gi02
         |         Paracooperia Gi02
         |         Rhabditolaimus L02a
         |         Ollulanus tricuspis L02a
         |         Probstmayria vivipara MM02
         |         Mesodiplogaster L02a
         |           |--M. biformis Ge02
         |           `--M. lheritieri L02a
         |         Labronema vulvapapillatum L02a
         |         Metadasynemoides cristatus L02b
         |         Acanthonchus duplicatus L02b
         |         Laxus oneistus L02b
         |         Prooncholaimus L02b
         |         Chromadorina L02c
         |           |--C. bioculata L02b
         |           `--C. viridis L02c
         |         Oswaldocruzia leidyi L02b
         |         Paracanthonchus caecus L02b, MV04
         |         Halichoanolaimus sonorus L02b
         |         Aporcellaimellus L02b
         |         Tachygonetria MM02
         |           |--T. robusta MM02
         |           `--T. stylosa MM02
         |         Brumptaemilius MM02
         |         Oxyspirura mansoni MM02
         |         Muellerius capillaris MM02
         |         Discolaimus MM02
         |         Rhadinaphelenchus cocophilus MM02
         |         Folyella dolichoptera L02c
         |         Mansonella Ge02
         |           |--M. ozzardi A71
         |           `--M. perstans Ge02
         |         Pseudorhabdolaimus Soos 1937 E86
         |           `--P. limnophilus Soos 1937 E86
         |         Zeldia punctata GR98
         |         Aduncospiculum halicti GR98
         |         Austronema Cobb 1914 BR05
         |         Longistrongylus curvispiculum KC07
         |         Spiroptera brevisubulata P89
         |         Controtylenchus brevicomi A-B91
         |         Stomachus marinus R59
         |         Ackertia marmotae Webster 1967 MW69
         |         Acarincola hirsutus Warren 1941 S69
         |         Nemavermes mackeei Schram 1973 G88
         |         Cyathostomum Molin 1861 [incl. Trichonema Cobbold 1874 non Ker Gawl. 1802 (ICBN)] C-SCL16
         |         Dorylaimopsis rabalaisi WXH10
         |         Vasostoma longispicula WXH10
         |         Stenolaimus lepturus PP64
         |         Scorpiophagus Størmer 1963 W93
         |           |--S. baculiformis Størmer 1963 W93
         |           `--S. latus Størmer 1963 W93
         |         Pulmostrongylus GC72
         |           |--P. fengi Hsü 1935 GC72
         |           `--P. herpestis (Khera 1956) GC72
         |         Arthrocephalus herpestis Khera 1956 GC72
         |         Diserratosomus mungoosii Mirza 1938 GC72
         |--Enoplea [Penetrantia] LB02
         |    |--Dorylaimia LB02
         |    `--Enoplia LB02
         `--Chromadorea [Chromadoria, Torquentia] LB02
              |  i. s.: Desmoscolecida LB02
              |--Monhysterida LB02
              `--+--Chromadorida LB02
                 `--+--Desmodorida LB02
                    `--+--Araeolaimida LB02
                       `--+--Plectida LB02
                          `--Secernentea LB02

*Type species of generic name indicated

REFERENCES

[A71] Askew, R. R. 1971. Parasitic Insects. Heinemann Educational Books: London.

[A-B91] Athias-Binche, F. 1991. Ecology and evolution of phoresy in mites. In: Dusbábek, F., & V. Bukva (eds) Modern Acarology: Proceedings of the VIII International Congress of Acarology, held in České Budĕjovice, Czechoslovakia, 6–11 August 1990 vol. 1 pp. 27–41. SPB Academic Publishing: The Hague.

[B02] Behm, C. A. 2002. Metabolism. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 261–290. Taylor & Francis: Florence (Kentucky).

[BR05] Bouchet, P., & J.-P. Rocroi. 2005. Classification and nomenclator of gastropod families. Malacologia 47 (1–2): 1–397.

[B01] Budd, G. E. 2001. Tardigrades as 'stem-group' arthropods: the evidence from the Cambrian fauna. Zoologischer Anzeiger 240: 265–279.

[C-SCL16] Cavalier-Smith, T., E. E. Chao & R. Lewis. 2016. 187-gene phylogeny of protozoan phylum Amoebozoa reveals a new class (Cutosea) of deep-branching, ultrastructurally unique, enveloped marine Lobosa and clarifies amoeba evolution. Molecular Phylogenetics and Evolution 99: 275–296.

[C02a] Collette, B. B. 2002a. Toadfishes. Order Batrachoididae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 261–264. Smithsonian Institute Press: Washington.

[C02b] Collette, B. B. 2002b. Dolphinfishes. Family Coryphaenidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 409–411. Smithsonian Institute Press: Washington.

[C92] Crawford, R. L. 1992. Catalogue of the genera and type species of the harvestman superfamily Phalangioidea (Arachnida). Burke Museum Contributions in Anthropology and Natural History 8: 1–60.

[E86] Eder, R. 1986. Nematoda from continental subterranean aquatic habitats. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) pp. 125–132. E. J. Brill/Dr W. Backhuys: Leiden.

[Ge02] Gems, D. 2002. Ageing. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 413–455. Taylor & Francis: Florence (Kentucky).

[GC72] Ghose, R. K., & Y. Chaturvedi. 1972. Extension of range of the mongoose, Herpestes palustris Ghose (Mammalia: Carnivora: Viverridae), with a note on its endoparasitic nematode. Journal of the Bombay Natural History Society 69 (2): 412–413.

[Gi02] Gibbons, L. M. 2002. General organisation. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 31–59. Taylor & Francis: Florence (Kentucky).

[GR98] Giribet, G., & C. Ribera. 1998. The position of arthropods in the animal kingdom: a search for a reliable outgroup for internal arthropod phylogeny. Molecular Phylogenetics and Evolution 9: 481–488.

[G88] Gray, J. 1988. Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology 62: 1–214.

[G01] Gupta, S. K. 2001. A conspectus of natural enemies of phytophagous mites and mites as potential biocontrol agents of agricultural pests in India. In: Halliday, R. B., D. E. Walter, H. C. Proctor, R. A. Norton & M. J. Colloff (eds) Acarology: Proceedings of the 10^th International Congress pp. 484–497. CSIRO Publishing: Melbourne.

[K-M02] Klein-MacPhee, G. 2002. Cods. Family Gadidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 223–261. Smithsonian Institute Press: Washington.

[KC07] Krausman, P. R., & A. L. Casey. 2007. Addax nasomaculatus. Mammalian Species 807: 1–4.

[L02a] Lee, D. L. 2002a. Life cycles. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 61–72. Taylor & Francis: Florence (Kentucky).

[L02b] Lee, D. L. 2002b. Cuticle, moulting and exsheathment. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 171–209. Taylor & Francis: Florence (Kentucky).

[L02c] Lee, D. L. 2002c. Behaviour. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 369–387. Taylor & Francis: Florence (Kentucky).

[LB02] Ley, P. de, & M. Blaxter. 2002. Systematic position and phylogeny. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 1–30. Taylor & Francis: Florence (Kentucky).

[L86] Lorenzen, S. 1986. Nematoda: Interstitial nematodes from marine brackish and hypersaline environments. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) pp. 133–142. E. J. Brill/Dr W. Backhuys: Leiden.

[MV04] Manylov, O. G., N. S. Vladychenskaya, I. A. Milyutina, O. S. Kedrova, N. P. Korokhov, G. A. Dvoryanchikov, V. V. Aleshin & N. B. Petrov. 2004. Analysis of 18S rRNA gene sequences suggests significant molecular differences between Macrodasyida and Chaetonotida (Gastrotricha). Molecular Phylogenetics and Evolution 30: 850–854.

[MW69] Moss, W. W., & W. A. Webster. 1969. A numerical taxonomic study of a group of selected strongylates (Nematoda). Systematic Zoology 18 (4): 423–443.

[MM02] Munn, E. A., & P. D. Munn. 2002. Feeding and digestion. In: Lee, D. L. (ed.) The Biology of Nematodes pp. 211–232. Taylor & Francis: Florence (Kentucky).

[Mun02] Munroe, T. A. 2002. Herrings. Family Clupeidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 111–160. Smithsonian Institute Press: Washington.

[Mus02] Musick, J. A. 2002. Sturgeons. Family Acipenseridae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 83–88. Smithsonian Institute Press: Washington.

[N02] Nizinski, M. S. 2002. Sand lances. Family Ammodytidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 496–505. Smithsonian Institute Press: Washington.

[OH17] Ou, Q., J. Han, Z. Zhang, D. Shu, G. Sun & G. Mayer. 2017. Three Cambrian fossils assembled into an extinct body plan of cnidarian affinity. Proceedings of the National Academy of Sciences of the USA 114 (33): 8835–8840.

[P89] Parona, C. 1889. Sopra alcuni elminti di Vertebrati birmani raccolti da Leonardo Fea. Annali del Museo Civico di Storia Naturale di Genova, Serie 2^a, 7: 765–780.

[PP64] Peres, J. M., & J. Picard. 1964. Nouveau manuel de bionomie benthique de la mer Mediterranee. Recueil des Travaux de la Station Marine d'Endoume, Bulletin 31 (27): 5–137.

[R59] Robinson, E. S. 1959. Records of cestodes from marine fishes of New Zealand. Transactions of the Royal Society of New Zealand 86 (1): 143–153.

[S69] Steyskal, G. C. 1969. The mistreatment of the Latin genitive case in forming names of parasites. Systematic Zoology 18 (3): 339–342.

[W93] Wills, M. A. 1993. Miscellania. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 555–560. Chapman & Hall: London.

[WXH10] Wu, X., K. Xu & Y. Huang. 2010. Community structure and spatial distribution of marine benthic nematodes at the late stage of the Yellow Sea macroalgal bloom in 2008. In: China-Russia Bilateral Symposium: Proceedings of the China-Russia Bilateral Symposium of "Comparison on Marine Biodiversity in the Northwest Pacific Ocean", 10–11 October 2010, Qingdao (China) pp. 147–148. Institute of Oceanology, Chinese Academy of Sciences; A. V. Zhirmunsky Institute of Marine Biology, Far East Branch of the Russian Academy of Sciences.

Beyrichioidea

Male (above) and female Kloedenia normalis, from Benson et al. (1961).

Belongs within: Palaeocopida.
Contains: Beyrichia.

The Beyrichioidea are a group of ostracods known from the mid-Ordovician to the early Permian characterised by the dimorphic development of a ventral to anteroventral lobe or pouch in females. The hinge of the carapace is straight but the Silurian Zygobolbidae have the lateral lobes L₂ and L₃ tending to project above the level of the dorsum (Benson et al. 1961).

Characters (from Benson et al. 1961): Straight-hinged ostracodes with subequal ends or forward swing, mostly with well-developed lobes and sulci and showing tendency to have carinal, velate, and marginal structures; dimorphism usually well defined.

Beyrichioidea [Beyrichiacea, Beyrichiomorphinina] L05
    |  i. s.: Gillatia Öpik 1953 BB61
    |           `--*G. trinacria Öpik 1953 BB61
    |--Treposellidae [Treposellinae] WSB93
    |    |--Loutriella jupiterensis Copeland 1974 WSB93
    |    |--Parabouckekius martinssoni Jones 1985 WSB93
    |    |--Katatona romei Jones 1985 WSB93
    |    `--Treposella Ulrich & Bassler 1908 BB61
    |         |--*T. lyoni (Ulrich 1891) [=Beyrichia lyoni] BB61
    |         `--T. stellata BB61
    |--Craspedobolbinidae WSB93
    |    |--Malnina spinosa Jones 1989 WSB93
    |    |--Armilla sibirica Bushmina 1975 WSB93
    |    |--Craspedobolbina Kummerow 1923 BB61
    |    |    `--*C. dietrichi Kummerow 1923 BB61
    |    |--Copelandella Bless & Jordan 1971 WSB93, G88
    |    |    `--C. novascotia (Jones & Kirby 1884) WSB93
    |    `--Bolbineossia Kesling, Heany et al. 1958 WSB93, BB61
    |         |--*B. didictyosa Kesling, Heany et al. 1958 BB61
    |         `--B. pineaulti Copeland 1974 WSB93
    |--Zygobolbidae [Zygobolbinae] BB61
    |    |--Bonnemaia Ulrich & Bassler 1923 BB61
    |    |    `--*B. celsa Ulrich & Bassler 1923 BB61
    |    |--Glymmatobolbina Harris 1957 BB61
    |    |    `--*G. quadrata Harrs 1957 BB61
    |    |--Mastigobolbina Ulrich & Bassler 1923 BB61
    |    |    `--*M. typa Ulrich & Bassler 1923 BB61
    |    |--Plethobolbina Ulrich & Bassler 1923 BB61
    |    |    `--*P. typicalis Ulrich & Bassler 1923 BB61
    |    `--Zygobolba Ulrich & Bassler 1923 BB61
    |         |--*Z. (Zygobolba) decora (Billings 1866) [=Beyrichia decora] BB61
    |         |--Z. (Zygobolbina Ulrich & Bassler 1923) BB61
    |         |    `--Z. (*Z.) conradi (Ulrich & Bassler 1923) [=*Zygobolbina conradi] BB61
    |         `--Z. (Zygosella Ulrich & Bassler 1923) BB61
    |              `--Z. (*Z.) vallata (Ulrich & Bassler 1923) [=*Zygosella vallata] BB61
    |--Kloedenia Jones & Holl 1886 BB61 [Kloedeniidae L05, Kloedeniinae, Kloedeninae]
    |    |--*K. wilckensiana (Jones 1855) [=Beyrichia wilckensiana] BB61
    |    |--K. apiculata Jones 1888 C01
    |    |--K. australis Chapman 1920 F71
    |    |--K. fifieldensis Chapman 1920 F71
    |    |--K. gotlandica Chapman 1901 C01
    |    |--K. normalis BB61
    |    `--K. sussexensis BB61
    |--Ochescaphidae L05
    `--Beyrichiidae [Beyrichiinae, Beyrichinae] BB61
         |--Fallaticella schaeferi Schallreuter 1984 WSB93
         |--Apatobolbina Ulrich & Bassler 1923 BB61
         |    `--*A. granifera Ulrich & Bassler 1923 BB61
         |--Bolbibollia Ulrich & Bassler 1923 BB61
         |    `--*B. labrosa Ulrich & Bassler 1923 BB61
         |--Bolbiprimitia Kay 1940 BB61
         |    `--*B. fissurella (Ulrich & Bassler 1923) [=Halliella fissurella] BB61
         |--Cornikloedenia Henningsmoen 1954 BB61
         |    `--*C. ventralis (Ulrich & Bassler 1923) [=Drepanellina ventralis] BB61
         |--Ctenobolbinella Kummerow 1953 BB61
         |    `--*C. carinata Kummerow 1953 BB61
         |--Dolichoscapha Kesling & Ehlers 1958 BB61
         |    `--*D. escharota Kesling & Ehlers 1958 BB61
         |--Drepanellina Ulrich & Bassler 1923 BB61
         |    `--*D. clarki Ulrich & Bassler 1923 BB61
         |--Halliella Ulrich 1891 BB61
         |    `--*H. retifera Ulrich 1891 BB61
         |--Hibbardia Kesling 1953 BB61
         |    `--*H. lacrimosa (Swartz & Oriel 1948) [=Amphissites lacrimosus] BB61
         |--Mesomphalus Ulrich & Bassler 1913 [=Mezomphalus Zaspelova 1952] BB61
         |    `--*M. hartleyi Ulrich & Bassler 1913 BB61
         |--Myomphalus Swartz & Whitmore 1956 BB61
         |    `--*M. dorsinodosus Swartz & Whitmore 1956 BB61
         |--Phlyctiscapha Kesling 1953 BB61
         |    `--*P. rockportensis Kesling 1953 BB61
         |--Pseudobeyrichia Swartz & Whitmore 1956 BB61
         |    `--*P. perornata Swartz & Whitmore 1956 BB61
         |--Saccarchites Swartz & Whitmore 1956 BB61
         |    `--*S. saccularis Swartz & Whitmore 1956 BB61
         |--Welleria Ulrich & Bassler 1923 BB61
         |    `--*W. obliqua Ulrich & Bassler 1923 BB61
         |--Bodenia Ivanova 1959 LH61
         |    `--*B. aspera Ivanova 1959 LH61
         |--Pseudoleperditia Schneider 1956 WSB93, BB61
         |    `--*P. tuberculifera Schneider 1956 BB61
         |--Dibolbina Ulrich & Bassler 1923 BB61
         |    |--*D. cristata Ulrich & Bassler 1923 BB61
         |    `--D. steusloffi BB61
         |--Lophokloedenia Swartz & Whitmore 1956 BB61
         |    |--*L. manliensis (Weller 1903) [=Beyrichia manliensis] BB61
         |    `--L. kummeli BB61
         |--Welleriopsis Swartz & Whitmore 1956 BB61
         |    |--*W. diplocystulis Swartz & Whitmore 1956 BB61
         |    `--W. jerseyensis BB61
         |--Zygobeyrichia Ulrich 1916 BB61
         |    |--*Z. apicalis Ulrich 1916 BB61
         |    `--Z. barretti BB61
         |--Kyamodes Jones 1888 [=Kyammodes Ulrich & Bassler 1908] BB61
         |    |--*K. whidbornei Jones 1888 BB61
         |    |--K. kiesowi BB61
         |    `--K. tricornis BB61
         `--Beyrichia BB61

*Type species of generic name indicated

REFERENCES

[BB61] Benson, R. H., J. M. Berdan, W. A. van den Bold, T. Hanai, I. Hessland, H. V. Howe, R. V. Kesling, S. A. Levinson, R. A. Reyment, R. C. Moore, H. W. Scott, R. H. Shaver, I. G. Sohn, L. E. Stover, F. M. Swain & P. C. Sylvester-Bradley. 1961. Systematic descriptions. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt Q. Arthropoda 3: Crustacea: Ostracoda pp. Q99–Q421. Geological Society of America and University of Kansas Press.

[C01] Chapman, F. 1901. On some fossils of Wenlock age from Mulde, near Klinteberg, Gotland; with notes by Prof. T. Rupert Jones and Dr. F. A. Bather. Annals and Magazine of Natural History, series 7, 7: 141–160, pl. 3.

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.

[G88] Gray, J. 1988. Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology 62: 1–214.

[LH61] Levinson, S. A., & H. V. Howe. 1961. Addendum. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt Q. Arthropoda 3: Crustacea: Ostracoda pp. Q421–Q422. Geological Society of America and University of Kansas Press.

[L05] Liebau, A. 2005. A revised classification of the higher taxa of the Ostracoda (Crustacea). Hydrobiologia 538: 115–137.

[WSB93] Whatley, R. C., D. J. Siveter & I. D. Boomer. 1993. Arthropoda (Crustacea: Ostracoda). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 343–356. Chapman & Hall: London.

Euchelicerata

Prokoenenia wheeleri, copyright Robert Deans.

Belongs within: Euarthropoda.
Contains: Koupichela, Parasitiformes, Pseudoscorpiones, Acariformes, Phalangiotarbida, Opiliones, Xiphosura, Ricinulei, Scorpiones, Trigonotarbida, Tetrapulmonata, Solifugae, Eukoeneniidae.

The Euchelicerata are a major clade of arthropods uniting the arachnids (spiders, mites, scorpions and related taxa) with their living and fossil marine relatives. A potential synapomorphy is the presence of multilobate exopods on post-cephalic limbs that are covered by a sclerite or operculum though this feature has been lost in most living groups (Aria & Caron 2019). The monophyly of the arachnids has been subject to some debate, with some authors suggesting that 'arachnid' characters may represent convergent adaptations to terrestriality. Recent molecular phylogenetic analyses have suggested that the horseshoe crabs, long thought to be the only surviving primarily aquatic euchelicerates, may be nested within the arachnid crown group. Other relationships within the Euchelicerata are similarly contentious with a wide array of arrangements having been proposed at one time or another, few of them strongly supported. A relationship between the Tetrapulmonata (including spiders and whip scorpions) and the fossil Trigonotarbida is supported by features including cheliceral structure, presence of a megoperculum, and booklungs on the genital and first post-genital somites (Shultz 2007). Molecular analyses have also supported a relationship between Tetrapulmonata and Scorpiones in a clade that has been named Arachnopulmonata and may be characterised by the presence of book lungs.

Particularly hard to place are the Palpigradi, a group of minute, segmented arachnids with with an elongate abdomen terminating in a whip-like, seta-bearing flagellum. Palpigrades inhabit damp habitats such as soil or leaf litter with members of the genus Leptokoenenia inhabiting interstitial habitats along shorelines. The Jurassic fossil Sternarthron zitteli has been assigned to the Palpigradi but is considerably larger than any living species and may be misplaced (Harvey 2002).

The mites are a diverse assemblage of mostly very small arachnids commonly treated as a formal group Acari or Acarina. Mites have been divided between two major lineages: the Acariformes have birefringent setae with a core of actinopilin whereas the Parasitiformes (or Anactinotrichida) lack such setae. Whether the mites as a whole represent a monophyletic group remains a contested issue. Mite larvae have only six walking legs when they first emerge, with the fourth pair developing in later instars. This feature is shared with the Ricinulei, leading some authors to suggest a relationship between mites and ricinuleids, but other analyses have placed the groups separately.

<==Euchelicerata [Merostomata, Myliosomata, Synxiphosurina, Xiphosuridea] RS10
    |  i. s.: Melbournopterus crossotus Caster & Kjellesvig-Waering 1953 TB04
    |         Venustulus waukeshaensis BS12
    |         Lunatapsis aurora JB12
    |         Eolimulus ([Eolimulidae] S93
    |           `--E. alatus (Moberg 1892) S93
    |--+--Dibasterium Briggs, Siveter et al. 2012 AC19, BS12
    |  |    `--*D. durgae Briggs, Siveter et al. 2012 BS12
    |  `--+--Sarotrocercus Whittington 1981 LSE13, CB04
    |     `--Offacolus [Offacolidae] AC17
    |          `--O. kingi Orr, Siveter et al. 2000 SB02
    `--Arachnida (see below for synonymy) BSL19
         |  i. s.: Enyo E12
         |           |--E. algirica Lucas 1846 E12
         |           `--E. amaranthina Lucas 1846 E12
         |         Cyrtocephalus Lucas 1846 E12
         |           |--C. terricola Lucas 1846 E12
         |           `--C. walckenaerii Lucas 1846 E12
         |         Monastes Lucas 1846 E12
         |           |--M. lapidarius Lucas 1846 E12
         |           `--M. paradoxus Lucas 1846 E12
         |         Hemialges F54
         |         Falculifera echinopus F54
         |         Hygrochoreutes krameri BK91
         |         Tenuipalponychus citri G91
         |         Beerella depicta W99
         |         Sonotetranychus albiflorae W99
         |         Pachylichus Canestrini 1894 [=Pachylicus (l. c.) non Roewer 1923] KA-Z11
         |         Fonsecia ptyasi Rao & Hiregander 1959 S69
         |         Hoshikadania Sasa & Asanuma 1951 S94
         |         Trichadenus Rondani 1870 CF77
         |         Crocidurobia michaeli GHG91
         |         Tapinattus melanognathus (see below for synonymy) S99
         |         Diacrotricha Oudem. 1906 B28
         |         Gamasides Leach 1814 B28
         |         Greeniella R13
         |           |--G. alfkeni R13
         |           `--G. perkensi R13
         |         Chaetozythia Karst. 1888 (n. d.) KC01
         |         Alanops LSE13
         |         Weinberginidae S93
         |           |--Weinbergina opitzi Richter & Richter 1929 AC19, CB04
         |           `--Legrandella lombardii Eldredge 1974 S93
         |         Koupichela AC19
         |         Astoma parasiticum G20
         |--+--Parasitiformes BSL19
         |  `--+--Pseudoscorpiones BSL19
         |     `--Acariformes BSL19
         `--+--+--Phalangiotarbida GD16
            |  `--Opiliones BSL19
            `--+--+--+--Xiphosura BSL19
               |  |  `--Ricinulei BSL19
               |  `--Arachnopulmonata BSL19
               |       |--Scorpiones BSL19
               |       `--Pantetrapulmonata GD14
               |            |  i. s.: Ecchosis pulchribothrium Selden & Shear 1991 S93
               |            |--Trigonotarbida GD16
               |            |--Tetrapulmonata BSL19
               |            `--Mesotarbus LSE13
               |                 |--M. angustus (Pocock 1911) S93
               |                 |--M. eggintoni (Pocock 1911) S93
               |                 |--M. hindi S93
               |                 `--M. intermedius Petrunkevitch 1949 S93
               `--+--Solifugae BSL19
                  `--Palpigradi [Microteliphonida] BSL19
                       |  i. s.: Triadokoenenia HST06
                       |         Allokoenenia afra Silvestri 1913 HST06
                       |         Leptokoenenia M86
                       |           |--L. gerlachi Condé 1965 M86
                       |           `--L. scurra Monniot 1966 M86
                       |         Koeneniodes HST06
                       |           |--K. berndi Condé 1988 HST06
                       |           |--K. deharvengi HST06
                       |           |--K. frondiger Rémy 1950 HST06
                       |           |--K. leclerci HST06
                       |           |--K. madecassus Rémy 1950 HST06
                       |           |--K. malagasorum Rémy 1960 HST06
                       |           |--K. notabilis HST06
                       |           `--K. spiniger HST06
                       |--Eukoeneniidae S93
                       |--Prokoenenia [Prokoeneniidae] HST06
                       |    `--P. wheeleri GE02
                       `--Sternarthron Haase 1890 H02 [Sternarthronidae S93]
                            `--*S. zitteli Haase 1890 H02

Arachnida [Acari, Acarida, Acaridiae, Acarina, Acarinomorpha, Acaromorpha, Actinoderma, Apatellata, Apulmonata, Arthrogastra, Chelodonta, Cryptognomae, Cryptoperculata, Dromopoda, Epimerata, Galeodides, Haplocnemata, Holacarina, Holotracheata, Lipoctena, Meridogastra, Microphtira, Micrura, Neosternata, Novogenuata, Obisides, Pedipalpata, Phalangiata, Phalangita, Poecilophysidea, Riciniae, Rostrosomata, Scorpionides, Solenostoma, Solpugae, Sternocoxata, Stomothecata, Synziphosurina, Xiphosurida]

Tapinattus melanognathus [=Attus melanognathus; incl. Salticus convergens Doleschall 1859, Marpissa dissimilis Koch 1846, M. incerta Koch 1846, Attus muscivorus Vinson 1864, Salticus nigrolimbatus Cambr. 1869] S99

*Type species of generic name indicated

REFERENCES

[AC17] Aria, C., & J.-B. Caron. 2017. Burgess Shale fossils illustrate the origin of the mandibulate body plan. Nature 545: 89–92.

[AC19] Aria, C., & J.-B. Caron. 2019. A middle Cambrian arthropod with chelicerae and proto-book gills. Nature 573: 586–589.

[BSL19] Ballesteros, J. A., C. E. Santibáñez López, Ľ. Kováč, E. Gavish-Regev & P. P. Sharma. 2019. Ordered phylogenomic subsampling enables diagnosis of systematic errors in the placement of the enigmatic arachnid order Palpigradi. Proceedings of the Royal Society of London Series B—Biological Sciences 286: 20192426.

[B28] Betrem, J. G. 1928. Monographie der Indo-Australischen Scoliiden mit zoogeographischen Betrachtungen. H. Veenman & Zonen: Wageningen.

[BK91] Biesiadka, E., & W. Kowalik. 1991. Water mites (Hydracarina) as indicators of trophy and pollution in lakes. In: Dusbábek, F., & V. Bukva (eds) Modern Acarology: Proceedings of the VIII International Congress of Acarology, held in České Budĕjovice, Czechoslovakia, 6–11 August 1990 vol. 1 pp. 475–481. SPB Academic Publishing: The Hague.

[BS12] Briggs, D. E. G., D. J. Siveter, D. J. Siveter, M. D. Sutton, R. J. Garwood & D. Legg. 2012. Silurian horseshoe crab illuminates the evolution of arthropod limbs. Proceedings of the National Academy of Sciences of the USA 109 (39): 15702–15705.

[CF77] Canestrini, G., & F. Fanzago. 1877. Intorno agli Acari Italiani. Atti del Reale Istituto Veneto di Scienze, Lettere ed Arti, Serie 5, 4: 69–208, pls 2–7.

[CB04] Cotton, T. J., & S. J. Braddy. 2004. The phylogeny of arachnomorph arthropods and the origin of the Chelicerata. Transactions of the Royal Society of Edinburgh: Earth Sciences 94: 169–193.

[E12] Evenhuis, N. L. 2012. Publication and dating of the Exploration Scientifique de l'Algérie: Histoire Naturelle des Animaux Articulés (1846–1849) by Pierre Hippolyte Lucas. Zootaxa 3448: 1–61.

[F54] Forster, R. R. 1954. The New Zealand harvestmen (sub-order Laniatores). Canterbury Museum Bulletin 2: 1–329.

[GHG91] Gállego, M., E. Hidalgo & J. Ginés. 1991. Mites of the house mouse, Mus musculus L., in the north-eastern part of the Iberian Peninsula in Spain. In: Schuster, R., & P. W. Murphy (eds) The Acari: Reproduction, development and life-history strategies pp. 453–454. Chapman & Hall: London.

[GD14] Garwood, R. J., & J. Dunlop. 2014. Three-dimensional reconstruction and the phylogeny of extinct chelicerate orders. PeerJ 2: e641.

[GD16] Garwood, R. J., J. A. Dunlop, P. A. Selden, A. R. T. Spencer, R. C. Atwood, N. T. Vo & M. Drakopoulos. 2016. Almost a spider: a 305-million-year-old fossil arachnid and spider origins. Proceedings of the Royal Society of London Series B—Biological Sciences 283: 20160125.

[GE02] Giribet, G., G. D. Edgecombe, W. C. Wheeler & C. Babbitt. 2002. Phylogeny and systematic position of Opiliones: a combined analysis of chelicerate relationships using morphological and molecular data. Cladistics 18: 5–70.

[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.

[G91] Gupta, S. K. 1991. The mites of agricultural importance in India with remarks on their economic status. In: Dusbábek, F., & V. Bukva (eds) Modern Acarology: Proceedings of the VIII International Congress of Acarology, held in České Budĕjovice, Czechoslovakia, 6–11 August 1990 vol. 1 pp. 509–522. SPB Academic Publishing: The Hague.

[H02] Harvey, M. S. 2002. The neglected cousins: what do we know about the smaller arachnid orders? Journal of Arachnology 30 (2): 357–372.

[HST06] Harvey, M. S., F. Štáhlavský & P. D. Theron. 2006. The distribution of Eukoenenia mirabilis (Palpigradi: Eukoeneniidae): a widespread tramp. Records of the Western Australian Museum 23 (2): 199–203.

[JB12] Johnson, M. E., & B. G. Baarli. 2012. Development of intertidal biotas through Phanerozoic time. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 63–128. Springer.

[KC01] Kirk, P. M., P. F. Cannon, J. C. David & J. A. Stalpers. 2001. Ainsworth & Bisby's Dictionary of the Fungi 9^th ed. CAB International: Wallingford (UK).

[KA-Z11] Kury, A. B., & M. A. Alonso-Zarazaga. 2011. Addenda and corrigenda to the "Annotated catalogue of the Laniatores of the New World (Arachnida, Opiliones)". Zootaxa 3034: 47–68.

[LSE13] Legg, D. A., M. D. Sutton & G. D. Edgecombe. 2013. Arthropod fossil data increase congruence of morphological and molecular phylogenies. Nature Communications 4 (2485): 1-7.

[M86] Monniot, F. 1986. Palpigradi. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) p. 697. E. J. Brill/Dr W. Backhuys: Leiden.

[R13] Reuter, O. M. 1913. Lebensgewohnheiten und Instinkte der Insekten bis zum Erwachen der sozialen Instinkte. R. Friedländer & Sohn: Berlin.

[S93] Selden, P. A. 1993. Arthropoda (Aglaspidida, Pycnogonida and Chelicerata). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 297–320. Chapman & Hall: London.

[S99] Simon, E. 1899. Ergebnisse einer Reise nach dem Pacific (Schauinsland 1896–1897. Zoologische Jahrbücher, Abteilung für Systematik, Geographie un Biologie der Thiere 12 (4): 411–437.

[S94] Southcott, R. V. 1994. Revision of the larvae of the Microtrombidiinae (Acarina, Microtrombidiidae), with notes on life histories. Zoologica 48 (2): 1–155.

[S69] Steyskal, G. C. 1969. The mistreatment of the Latin genitive case in forming names of parasites. Systematic Zoology 18 (3): 339–342.

[SB02] Sutton, M. D., D. E. G. Briggs, D. J. Siveter, D. J. Siveter & P. J. Orr. 2002. 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: 1195–1203.

[TB04] Tetlie, O. E., S. J. Braddy, P. D. Butler & D. E. G. Briggs. 2004. A new eurypterid (Chelicerata: Eurypterida) from the Upper Devonian Gogo Formation of Western Australia, with a review of the Rhenopteridae. Palaeontology 47 (4): 801–809.

[WD02] Waloszek, D., & J. A. Dunlop. 2002. A larval sea spider (Arthropoda: Pycnogonida) from the Upper Cambrian ‘Orsten’ of Sweden, and the phylogenetic position of pycnogonids. Palaeontology 45 (3): 421–446.

[W99] Walter, D. E. 1999. Cryptic inhabitants of a noxious weed: mites (Arachnida: Acari) on Lantana camara L. invading forests in Queensland. Australian Journal of Entomology 38: 197–200.

Malacostraca

Paranebalia sp., from the Yale Peabody Museum of Natural History.

Belongs within: Euarthropoda.
Contains: Archaeostraca, Eumalacostraca, Nebaliidae.

The Malacostraca are a clade of crustaceans characterised by the possession of fourteen or fifteen trunk segments with the trunk divided into two sections bearing functionally distinct appendages. The anterior section of eight segments bears leaf-like phyllopods or rod-shaped stenopods whereas the following six segments bear swimming pleopods (there may be a terminal limbless segment). Those taxa with phyllopods have historically been recognised as the Phyllocarida but recent analysis have indicated this group is paraphyletic to the stenopod-bearing Eumalacostraca. 'Phyllocarida' are represented in the modern fauna by the Leptostraca which also bear a movable rostrum, a scale-like ramus on the first antenna, and a uniramous second antenna (Walker-Smith & Poore 2001).

<==Malacostraca [Phyllocarida]
    |--+--Archaeostraca AC17
    |  `--+--Cinerocaris magnifica AC17, SC17
    |     `--Eumalacostraca AC17
    `--Leptostraca [Nebaliacea] AC17
         |  i. s.: Rhabdouraea Malzahn 1962 [Rhabdouraeidae] W-SP01
         |           `--*R. bentzi (Malzahn 1958) [=Nebalia bentzi) SM84
         |         Douglasocaris [Douglasocaridae] G88
         |--Nebaliopsis Sars 1887 [Nebaliopsidae, Nebaliopsididae] W-SP01
         |    `--*N. typica Sars 1887 W-SP01
         `--+--Nebaliidae W-SP01
            `--Paranebaliidae W-SP01
                 |--Paranebalia Claus 1880 W-SP01
                 |    |--*P. longipes (Willemöes-Suhm 1875) [=Nebalia longipes] W-SP01
                 |    `--P. belizensis Modlin 1991 W-SP01
                 `--Levinebalia Walker-Smith 2000 W-SP01
                      |--*L. maria Walker-Smith 2000 W-SP01
                      `--L. fortunata (Wakabara 1976) W-SP01

Malacostraca incertae sedis:
  Litopenaeus vannamei TL03
  Shinkaia crosnieri WS10
  Callizoe Barrande 1872 (n. d.) M61
  Orozoe Barrande 1872 (n. d.) M61
  Hymenocaris Salter 1853 B95 [Hymenocarididae, Hymenostraca FGS04]
    |--H. oelandica O68
    `--H. vermicauda Salter 1853 BWW93
  Sairocarididae [Hoplostraca] G88
    |--Sairocaris elongata (Peach 1882) BWW93
    `--Kellibrooksia macrogaster Schram 1973 BWW93
  Mytocaris Chlupáč 1970 BT04
    |--M. klouceki Chlupáč 1970 BT04
    `--‘Buffalopterus’ verrucosus Kjellesvig-Waering & Heubusch 1962 BT04
  Galenocaris Wells 1944 BT04
    `--G. campbelli Wells 1944 BT04
  Lebesconteia Jones & Woodward 1899 BT04
  Nothozoe Barrande 1872 (n. d.) BT04
    |--*N. pollens Barrande 1872 BB61
    `--N. barrandei Chlupáč 1970 BT04
  Saccocaris Salter 1873 BT04
    |--S. major Salter 1873 BT04
    |--S. minor Jones & Woodward 1891 BT04
    `--S. tetragona Chapman 1903 BT04
  Trigonocarys Barrois 1891 BT04
  Peltocaris Salter 1862 [incl. Coronagraptus Hundt 1951] M14

*Type species of generic name indicated

REFERENCES

[AC17] Aria, C., & J.-B. Caron. 2017. Burgess Shale fossils illustrate the origin of the mandibulate body plan. Nature 545: 89–92.

[BB61] Benson, R. H., J. M. Berdan, W. A. van den Bold, T. Hanai, I. Hessland, H. V. Howe, R. V. Kesling, S. A. Levinson, R. A. Reyment, R. C. Moore, H. W. Scott, R. H. Shaver, I. G. Sohn, L. E. Stover, F. M. Swain & P. C. Sylvester-Bradley. 1961. Systematic descriptions. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt Q. Arthropoda 3: Crustacea: Ostracoda pp. Q99–Q421. Geological Society of America and University of Kansas Press.

[B95] Bousfield, E. L. 1995. A contribution to the natural classification of Lower and Middle Cambrian arthropods: food-gathering and feeding mechanisms. Amphipacifica 2: 3–34.

[BT04] Braddy, S. J., V. P. Tollerton Jr, P. R. Racheboeuf & R. Schallreuter. 2004. Eurypterids, phyllocarids, and ostracodes. In: Webby, B. D., F. Paris, M. L. Droser & I. G. Percival (eds) The Great Ordovician Biodiversification Event pp. 255–265. Columbia University Press.

[BWW93] Briggs, D. E. G., M. J. Weedon & M. A. Whyte. 1993. Arthropoda (Crustacea excluding Ostracoda). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 321–342. Chapman & Hall: London.

[FGS04] Feldmann, R. M., A. A. Garassino & C. E. Schweitzer. 2004. The presumed decapod, Palaeopemphix Gemmellaro, 1890, is a unique member of the Phyllocarida (Palaeopemphicida: Palaeopemphidae). Journal of Palaeontology 78: 340–348.

[G88] Gray, J. 1988. Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology 62: 1–214.

[M14] Maletz, J. 2014. The classification of the Pterobranchia (Cephalodiscida and Graptolithina). Bulletin of Geosciences 89 (3): 477–540.

[M61] Moore, R. C. 1961. Editorial note. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt Q. Arthropoda 3: Crustacea: Ostracoda pp. Q429. Geological Society of America and University of Kansas Press.

[O68] Öpik, A. A. 1968. Ordian (Cambrian) Crustacea Bradoriida of Australia. Commonwealth of Australia, Bureau of National Development, Bureau of Mineral Resources, Geology and Geophysics, Bulletin 103: 1–45.

[SM84] Schram, F. R., & E. Malzahn. 1984. The fossil leptostracan Rhabdouraea bentzi (Malzahn, 1958). Transactions of the San Diego Society of Natural History 20 (6): 95–98.

[SC17] Schwentner, M., D. J. Combosch, J. P. Nelson & G. Giribet. 2017. A phylogenomic solution to the origin of insects by resolving crustacean-hexapod relationships. Current Biology 27: 1818–1824.

[TL03] Thompson, F. L., Y. Li, B. Gomez-Gil, C. C. Thompson, B. Hoste, K. Vandemeulebroecke, G. S. Rupp, A. Pereira, M. M. De Bem, P. Sorgeloos & J. Swings. 2003. Vibrio neptunius sp. nov., Vibrio brasiliensis sp. nov. and Vibrio xuii sp. nov., isolated from the marine aquaculture environment (bivalves, fish, rotifers and shrimps). International Journal of Systematic and Evolutionary Microbiology 53: 245–252.

[W-SP01] Walker-Smith, G. K., & G. C. B. Poore. 2001. A phylogeny of the Leptostraca (Crustacea) with keys to families and genera. Memoirs of Museum Victoria 58 (2): 383–410.

[WS10] Wang, M., S. Sun, C. Li & X. Shen. 2010. Distinctive mitochondrial genome of the calanoid copepod Calanus sinicus, a useful molecular marker for phylogenetic and population studies. In: China-Russia Bilateral Symposium: Proceedings of the China-Russia Bilateral Symposium of "Comparison on Marine Biodiversity in the Northwest Pacific Ocean", 10–11 October 2010, Qingdao (China) pp. 187–192. Institute of Oceanology, Chinese Academy of Sciences; A. V. Zhirmunsky Institute of Marine Biology, Far East Branch of the Russian Academy of Sciences.

Last updated: 13 March 2022.

Euarthropoda

Reconstruction of Mollisonia plenovenatrix by J. Liang, from Aria & Caron (2019).

Belongs within: Arthropoda.
Contains: Pycnogonida, Euchelicerata, Artiopoda, Marrellomorpha, Myriapoda, Fuxianhuiida, Hymenocarina, Oligostraca, Allotriocarida, Tantulocarida, Thecostraca, Copepoda, Malacostraca.

The name Euarthropoda refers to the most exclusive clade formed by crown-group arthropods. Recent analyses agree on a division of living arthropods between three major clades, the Chelicerata, Myriapoda and Pancrustacea, with the latter two usually being united to form a clade of arthropods possessing mandibles. Fossil euarthropod taxa not belonging to these clades are best known from the Cambrian period with the exception of the Artiopoda (the clade including the trilobites). The Chelicerata have a single pair of pre-oral appendages, the chelicerae, that are usually adapted for manipulating food. The Cambrian Mollisoniidae are a group of likely stem-chelicerates characterised by a broad, helmet-like head shield bearing wide eye notches, seven free segments in the anterior portion of the trunk extending into short pleurae, and posterior trunk segments fused into a pygidium (Aria & Caron 2019).

The clade Pancrustacea includes the modern crustaceans and insects with the latter a derived subgroup of the former (Regier et al. 2010). This last grouping is primarily supported by molecular data; potential synapomorphies of the Pancrustacea have all become modified in various subclades. Relationships within the pancrustaceans remain subject to analysis. A relationship between the Tantulocarida and Thecostraca has been suggested on the basis of gonopore position in the two groups; tantulocarids and basal thecostracans are also both sessile parasites.

<==Euarthropoda (see below for synonymy)
    |  i. s.: Dala peilertae Müller 1983 ZS07
    |         Walossekia quinquespinosa Müller 1983 ZS07
    |--Panchelicerata AC19
    |    |--+--Sanctacaris Briggs & Collins 1988 AC19, CB04 [Sanctacarida, Sanctacaridea]
    |    |  |    |--‘Utahcaris’ orion Conway Morris & Robison 1988 B95
    |    |  |    `--Sanctacaris uncata Briggs & Collins 1988 WD02
    |    |  `--Habeliida B95
    |    |       |--Habelia Walcott 1912 AC19, CB04
    |    |       |    `--H. optata AC19
    |    |       `--Ecnomocaris LSE13
    |    `--Chelicerata AC19
    |         |  i. s.: Wisangocaris barbarahardyae Jago, García-Bellido & Gehling 2016 BS20
    |         |--Mollisoniidae [Mollisoniida] AC19
    |         |    |--Mollisonia Walcott 1912 AC19, CB04 [incl. Houghtonites Raymond 1931 AC19]
    |         |    |    |--*M. symmetrica Walcott 1912 [incl. M. rara Walcott 1912] AC19
    |         |    |    |--M. gracilis Walcott 1912 [=Houghtonites gracilis] AC19
    |         |    |    |--M. plenovenatrix Aria & Caron 2019 AC19
    |         |    |    `--M. sinica Zhang et al. 2002 AC19
    |         |    |--Thelxiope Simonetta & Delle Cave 1975 AC19
    |         |    |--Corcorania Jell 1980 AC19
    |         |    |    `--C. trispinosa AC19
    |         |    `--Urokodia Hou, Chen & Lu 1989 AC19
    |         |--Pycnogonida RS10
    |         `--Euchelicerata RS10
    `--+--Retifaciida LSE13
       |    |--Retifacies Hou, Chen & Lu 1989 LSE13, CB04
       |    |    `--R. abnormalis Hou et al. 1989 CB04
       |    `--+--Pygmaclypeatus LSE13
       |       `--+--+--Kiisortoqia AC19
       |          |  `--Siriocars LSE13
       |          `--Squamacula LSE13
       |               |--S. buckorum LSE13
       |               `--S. clypeatus LSE13
       `--+--Artiopoda AC19
          `--+--Marrellomorpha AC19
             `--+--Aquilonifer Briggs, Siveter et al. 2016 AC19, BS16
                |    `--*A. spinosus Briggs, Siveter et al. 2016 BS16
                `--Mandibulata (see below for synonymy) AC17
                     |  i. s.: Ercaia [Promandibulata] C12
                     |           `--E. minuscule C12
                     |         Musacaris LSE13
                     |         Cambropachycopidae LSE13
                     |           |--Cambropachycope clarksoni Walossek & Müller 1990 BWW93
                     |           `--Goticaris longispinosa Walossek & Müller 1990 BWW93
                     |         Devonopilio Tihelka, Tian & Cai 2020 P-GS21, TTC20
                     |           `--*D. hutchinsoni Tihelka, Tian & Cai 2020 TTC20
                     |--Myriapoda AC19
                     `--+--+--Fuxianhuiida AC19
                        |  `--Hymenocarina AC19
                        `--Pancrustacea (see below for synonymy) AC17
                             |  i. s.: Nippotantulus heteroxenus Huys, Ohtsuka & Boxshall 1994 MA01
                             |         Neomysis M02
                             |           |--N. americana M02
                             |           `--N. vulgaris CS77
                             |         Perosquilla armata K-MC02
                             |           |--P. a. armata K-MC02
                             |           `--P. a. capensis K-MC02
                             |         Mesosoma Otto 1821 C92
                             |         Mixodiaptomus laciniatus D51
                             |         Pleuroncodes planipes CH97
                             |         Phalangites priscus Münster 1836 D07
                             |         Cryptophthalmus Rafinesque 1814 BR05
                             |         Cymodocea Rafinesque 1814 BR05
                             |         ‘Cymodocea’ Leach 1818 nec Rafinesque 1814 nec Lamouroux 1816 BR05
                             |         ‘Dactylopus’ Claus 1862 non Gill 1859 BR05
                             |         Donovania Leach 1814 BR05
                             |         Orientalina Kolosnitsyna 1973 BR05
                             |         Pagodina van Beneden 1853 BR05
                             |         ‘Trichia’ de Haan 1839 non Haller 1768 BR05
                             |         ‘Typhis’ Risso 1816 non Montfort 1810 [Typhidae] BR05
                             |         Fenneropenaeus chinensis DH08
                             |         Limnadella kitei Girard 1854 DS89
                             |         Anatanais robusto BBB-S95
                             |         Anthonema Walther 1904 H75
                             |           `--*A. problematica Walther 1904 H75
                             |         ‘Acherusia’ Lucas 1846 non Laporte & Gory 1837 E12
                             |           `--A. dumerilii Lucas 1846 E12
                             |         Naesea edwardsii Lucas 1846 E12
                             |         Ovalia Latreille in Griffith & Pidgeon 1833 KA-Z11
                             |         Cycloidea FGS04
                             |           |--Cyclus de Koninck 1841 [incl. Paraprosopon Gemmellaro 1890] FGS04
                             |           `--Oonocarcinus Gemmellaro 1890 FGS04
                             |         Heymonsicambria EL11
                             |         Hymenodora glacialis CS77
                             |         Ozolus Latreille 1802 L02a
                             |           `--*O. gasterostei Latreille 1802 L02b (see below for synonymy)
                             |         Amymone L02b
                             |           |--A. baccha [=Monoculus bacchus] L02b
                             |           |--A. faunus [=A. fauna, Monoculus faunus] L02b
                             |           |--A. moenas L02b
                             |           |--A. satyrus [=A. satyra, Monoculus satyrus] L02b
                             |           |--A. silene [=A. silenus, Monoculus silenus] L02b
                             |           `--A. thyas L02b
                             |         Nauplius L02b
                             |           |--N. bracteatus [=Monoculus bracteatus] L02b
                             |           `--N. saltatorius [=Monoculus saltatorius] L02b
                             |         Microdentopus gryllotalpa PP64
                             |         Aristeomorpha foliacea PP64
                             |         Ligur ensiferus PP64
                             |         Paromola cuvieri PP64
                             |         Anamathia rissoana PP64
                             |         Ergasticus clouei PP64
                             |         Dorynchus thompsoni PP64
                             |         Cymopolia caroni PP64
                             |         Halopsyche de Saussure 1857 BR17
                             |         Palpipes Roth 1851 K18
                             |         Berndtia purpurea CG97
                             |         Trypetasa lampas CG97
                             |         Amblyops crozetii O01
                             |         Harpactocarcinus tumidus H79
                             |         Tuzoiidae O68
                             |           |--Tuzoia O68
                             |           `--*Dioxycaris argenta (Walcott 1888) [=Leperditia argenta, Isoxys argenta] O68
                             |         Corynuropsis Scott 1894 E00
                             |--Oligostraca AC19
                             `--Altocrustacea [Ostraca, Phyllopodomorpha, Thoracopoda] RS10
                                  |--Allotriocarida SC17
                                  `--Multicrustacea [Communostraca, Vericrustacea] SC17
                                       |  i. s.: Arenosicaris inflata SC17
                                       |--+--Tantulocarida LS02
                                       |  `--Thecostraca SC17
                                       `--+--Copepoda SC17
                                          `--Malacostraca SC17

Euarthropoda [Arachnata, Arachnomorpha, Aspidonia, Aspidota, Cormogonida, Eotrilobitacea, Myriochelata, Paradoxopoda, Polymeria, Skaracarida]

Mandibulata [Antennata, Atelocerata, Biantennata, Labiophora, Labrophora, Opisthogoneata, Tracheata] AC17

*Ozolus gasterostei Latreille 1802 L02b [incl. Argulus delphini L02b, Monoculus delphinus L02a, M. gyrini L02b]

Pancrustacea [Archoptera, Copepodoida, Copepodomorpha, Crustacea, Crustaceanomorpha, Entomostraca, Eucrustacea, Gymnota, Maxillopoda, Pneumonura, Progonomorpha, Pseudopoda, Tetraconata, Thecostracomorpha] AC17

*Type species of generic name indicated

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Last updated: 29 December 2021.