Mikko's Phylogeny Archive

Bilateralia – bilaterally symmetric animals

After Conway Morris, 1993

Alternative phylogeny after Peterson & Eernisse, 2001

Alternative phylogeny after Davidson, Peterson & Cameron, 1995

<==o Bilateralia (kaksikylkis-symmetriset eläimet; bilaterally symmetric animals)
   |?- †Priscansermarinus barnetti Collins & Rudkin, 1981; M.Camb. NWNAm.
   |?- †Siphusauctum gregarium O'Brien & Caron, 2012; M.Camb. NWNAm. [Siphusauctidae O'Brien & Caron, 2012]
   |--o Acoelomata (acoleomates; ruumiinontelottomat)
   |  |?-o Xenoturbellida (xenoturbellids) [has been recently treated as unusual deuterostome phylum]
   |  |  `--o Xenoturbella Westblad, 1949
   |  |     |-- X. bocki Westblad, 1949
   |  |     `-- X. westbladi
   |  `--+-- Gnathostomulida (gnathostomulids; kampaleukamadot)
   |     `-- Platyhelmithes (flatworms; laakamadot)
   `--o Coelomata (ruumiinontelolliset)
      |-- Protostomia (protostomes; alkusuiset)
      `-- Deuterostomia (deuterostomes; jälkisuiset)

<==o Bilateralia
   |--o Deuterostomia
   |  |-- Chordata
   |  `--o Ambulacraria
   |     |-- Echinodermata (piikkinahkaiset)
   |     `--+== Enteropneusta
   |        `-- Pterobranchia
   `--o Protostomia
      |--o Ecdysozoa
      |  |-- Chaetognatha
      |  `--+-- Gastrotricha
      |     `--+--+-- Tardigrada
      |        |  `--+-- Onychophora
      |        |     `-- Arthropoda
      |        `--+--+-- Nematoda
      |           |  `-- Nematomorpha
      |           `--+-- Priapulida
      |              `--+-- Kinorhyncha
      |                 `-- Loricifera
      `--o Lophotrochozoa
         |--o Brachiozoa
         |  |-- Phoronida
         |  `-- Brachiopoda
         `--+-- Ectoprocta
            |-- Entoprocta
            |--+-- Nemertea
            |  `--+-- Sipuncula
            |     `--+-- Mollusca
            |        `--+-- Echiura
            |           `-- Annelida
            `--+-- Rotifera (rataseläimet)
               |-- Cycliophora
               `--+-- Gnathostomulida
                  `-- Platyhelmithes

<==o Bilateralia
   |-- Nematomorpha
   |-- Platyhelmithes
   `--o Coelomata
      |-- Nemertea
      |--+-- Mollusca
      |  `-- Sipuncula
      |-- Echiura
      |--+-- Annelida
      |  `-- Arthropoda
      `--o ?Deuterostoma
         |-- Phoronida
         `--+-- Brachiopoda
            `--o Deuterostoma sensu traditionalis
               |-- Echinodermata
               `--+-- Pterobranchia
                  `--+-- Enteropneusta
                     `-- Chordata

Reference(s):

• O'Brien, L. J. & Caron, J.-B., 2012: A New Stalked Filter-Feeder from the Middle Cambrian Burgess Shale, British Columbia, Canada.
  –Plos One: Vol. 7, #1, pp. e29233 [doi: 10.1371/journal.pone.0029233]
• Conway Morris, S., 1993: The fossil record and early evolution of the Metazoa.
  –Nature, vol. 361, 21 January, pp. 219-225
• Davidson, E. H., Peterson, K. J. & Cameron, R. A., 1995: Origin of bilaterian body plans: Evolution of developmental regulatory mechanisms.
  –Science: Vol. 270, 24 November, pp. 1319-1325
• Hou, X. & Bergström, J., 1997: Arthropods of the Lower Cambrian Chengjiang fauna, southwest China.
  –Fossils & Strata, Number 45, 22nd December 1997, pp. 1-116
• –iNet: The Tree of Life
• Parker, S. P. (ed.), 1982: Synopsis and classification of living organisms. Vols. 1 & 2
  –McGrew-Hill Book Company