Deuterostomia

Specimen of Vetulicola cuneata (scale bar 5 mm), with close-up of lateral groove structure (scale bar 1 mm), from Donoghue & Purnell (2009).

Belongs within: Eumetazoa.
Contains: Vetulicolia, Hemichordata, Echinodermata, Urochordata, Craniata.

The Deuterostomia are a group of animals characterised by features of embryonic development including radial cleavage, and development of the blastopore into the anus. Possible synapomorphies of this group (albeit lost or modified in many subgroups) also include the presence of gill slits and the endostyle (Shu et al. 2001).

The Chordata includes those animals in which the body has a notochord, a stiffening rod of cartilage running through the dorsum, during at least part of the life cycle (in vertebrates, this is replaced by the spine during embryonic development). Other synapomorphies include the presence of somites, a dorsal nerve cord, and a hypophysis (pituitary gland) (Bourlat et al. 2006). Modern molecular phylogenies support a basal position within the Chordata for the Cephalochordata, lancelets: small, superficially fish-like marine animals that primarily live buried in sand with the head exposed for filter-feeding.

<==Deuterostomia [Cyrtotreta, Dexiothetica, Pharyngotremata, Pikaiidae]
    |  i. s.: Phlogites Luo & Huo 1999 [incl. Cheungkongella Shu, Chen et al. 2001]C12
    |           |--*Cheungkongella’ ancestralis Shu, Chen et al. 2001SC01
    |           `--P. longusC12
    |--+--Saccorhytus Han, Shu et al. in Han, Conway Morris et al. 2017 [Saccorhytida, Saccorhytidae]HCM17
    |  |    `--*S. coronarius Han, Shu et al. in Han, Conway Morris et al. 2017HCM17
    |  `--+--VetulicoliaHCM17
    |     `--Vetulocystidae [Vetulocystida]SCM04
    |          |--Vetulocystis Shu, Conway Morris et al. 2004HCM17, SCM04
    |          |    `--*V. catenata Shu, Conway Morris et al. 2004SCM04
    |          `--Dianchicystis Shu, Conway Morris et al. 2004SCM04
    |               `--*D. jianshanensis Shu, Conway Morris et al. 2004SCM04
    |--Ambulacraria [Coelomopora]SCM04
    |    |--HemichordataSCM04
    |    `--+--EchinodermataSCM04
    |       `--+--Herpetogaster Chen 2012EL11, C12
    |          |    `--*H. collinsi Chen 2012C12
    |          `--EldoniidaeC12
    |               |--Eldonia ludwigi Walcott 1911WS93
    |               |--Stellostomites eumorphus Sun & Hou 1987WS93 [incl. Yunnanomedusa eleganta Sun & Hou 1987C12, WS93]
    |               |--PararotadiscusC12
    |               `--Rotadiscus grandisC12
    `--Chordata [Acraniata, Chordonia, Euchordata]SCM04
         |  i. s.: Emmonsaspis Resser & Howell 1938Ha62
         |           `--*E. cambrensis (Walcott 1890) [=Phyllograptus cambrensis]Ha62
         |--OlfactoresBJ06
         |    |--UrochordataBJ06
         |    `--+--Pikaia Walcott 1911MS16, Ho62
         |       |    `--*P. gracilens Walcott 1911Ho62
         |       `--CristozoaC12
         |            |--CraniataSCMH03
         |            `--Yunnanozoa [Procraniata, Yunnanozoida, Yunnanozoonidae]SCMZ03
         |                 |--*Yunnanozoon lividum Hou et al. 1991SCMZ03, C12, D95
         |                 `--Haikouella Chen, Huang & Li 1999SCMZ03
         |                      |--*H. lanceolataSCMZ03
         |                      `--H. jianshanensis Shu, Conway Morris et al. 2003SCMZ03
         `--Cephalochordata [Acrania]BJ06
              |  i. s.: Dolichorhynchus Willey 1901S00
              |         Palaeobranchiostoma hamatotergumB93
              |--Cathaymyrus diadexusEL11, CM98
              `--+--EpigonichthysBJ06
                 |    |--E. benhamiHS01
                 |    |--E. hectoriHS01
                 |    `--E. lucayanusBJ06
                 `--BranchiostomaBJ06
                      |--B. belcheriBJ06
                      |--B. caribbaeumE97
                      |--B. floridae Hubbs 1922C05
                      `--B. lanceolatum [=Limax lanceolatus]G03

*Type species of generic name indicated

References

[B93] Benton, M. J. 1993. Basal deuterostomes (chaetognaths, hemichordates, calcichordates, cephalochordates and tunicates). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 529–535. Chapman & Hall: London.

[BJ06] Bourlat, S. J., T. Juliusdottir, C. J. Lowe, R. Freeman, J. Aronowicz, M. Kirschner, E. S. Lander, M. Thorndyke, H. Nakano, A. B. Kohn, A. Heyland, L. L. Moroz, R. R. Copley & M. J. Telford. 2006. Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida. Nature 444 (7115): 85–89.

[C05] Cameron, C. B. 2005. A phylogeny of the hemichordates based on morphological characters. Canadian Journal of Zoology 83: 196–215.

[C12] Chen, J.-Y. 2012. Evolutionary scenario of the early history of the animal kingdom: evidence from Precambrian (Ediacaran) Weng’an and Early Cambrian Maotianshan biotas, China. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 239–379. Springer.

[CM98] Conway Morris, S. 1998. The Crucible of Creation. Oxford University Press: Oxford.

[D95] Dzik, J. 1995. Yunnanozoon and the ancestry of chordates. Acta Palaeontologica Polonica 40: 341–360.

[E97] Emig, C. C. 1997. Ecology of inarticulated brachiopods. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 473–495. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[EL11] Erwin, D. H., M. Laflamme, S. M. Tweedt, E. A. Sperling, D. Pisani & K. J. Peterson. 2011. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science 334: 1091–1097.

[G03] Gee, H. 2003. You aren’t what you eat. Nature 424: 885–886.

[HCM17] Han, J., S. Conway Morris, Q. Ou, D. Shu & H. Huang. 2017. Meiofaunal deuterostomes from the basal Cambrian of Shaanxi (China). Nature 542: 228–231.

[Ha62] Häntzschel, W. 1962. Trace fossils and problematica. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt W. Miscellanea: Conodonts, Conoidal Shells of Uncertain Affinities, Worms, Trace Fossils and Problematica pp. W177–W245. Geological Society of America, and University of Kansas Press.

[HS01] Hayward, B. W., A. B. Stephenson, M. S. Morley, W. M. Blom, H. R. Grenfell, F. J. Brook, J. L. Riley, F. Thompson & J. J. Hayward. 2001. Marine biota of Parengarenga Harbour, Northland, New Zealand. Records of the Auckland Museum 37: 45–80.

[Ho62] Howell, B. F. 1962. Worms. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt W. Miscellanea: Conodonts, Conoidal Shells of Uncertain Affinities, Worms, Trace Fossils and Problematica pp. W144–W177. Geological Society of America, and University of Kansas Press.

[MS16] McCoy, V. E., E. E. Saupe, J. C. Lamsdell, L. G. Tarhan, S. McMahon, S. Lidgard, P. Mayer, C. D. Whalen, C. Soriano, L. Finney, S. Vogt, E. G. Clark, R. P. Anderson, H. Petermann, E. R. Locatelli & D. E. G. Briggs. 2016. The ‘Tully monster’ is a vertebrate. Nature 532: 496–499.

[SC01] Shu, D.-G., L. Chen, J. Han & X.-L. Zhang. 2001. An Early Cambrian tunicate from China. Nature 411: 472–473.

[SCMH03] Shu, D.-G., S. Conway Morris, J. Han, Z.-F. Zhang, K. Yasul, P. Janvier, L. Chen, X.-L. Zhang, J.-N. Liu, Y. Li & H.-Q. Liu. 2003. Head and backbone of the Early Cambrian vertebrate Haikouichthys. Nature 421: 526–529.

[SCM04] Shu, D.-G., S. Conway Morris, J. Han, Z.-F. Zhang & J.-N. Liu. 2004. Ancestral echinoderms from the Chengjiang deposits of China. Nature 430: 422–428.

[SCMZ03] Shu, D., S. Conway Morris, Z. F. Zhang, J. N. Liu, J. Han, L. Chen, X. L. Zhang, K. Yasui & Y. Li. 2003. A new species of yunnanozoan with implications for deuterostome evolution. Science 299: 1380–1384.

[S00] Siddiqi, M. R. 2000. Tylenchida: Parasites of plants and insects 2nd ed. CABI Publishing: Wallingford (UK).

[WS93] Wills, M. A., & J. J. Sepkoski Jr. 1993. Problematica. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 543–554. Chapman & Hall: London.

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