Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida

@article{Bourlat2006DeuterostomePR,
  title={Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida},
  author={Sarah J. Bourlat and Thorhildur Juliusdottir and Christopher J. Lowe and Robert M. Freeman and Jochanan Aronowicz and Mark Kirschner and Eric S. Lander and Michael C. Thorndyke and Hiroaki Nakano and Andrea B. Kohn and Andreas Heyland and Leonid L. Moroz and Richard R. Copley and Maximilian J. Telford},
  journal={Nature},
  year={2006},
  volume={444},
  pages={85-88}
}
Deuterostomes comprise vertebrates, the related invertebrate chordates (tunicates and cephalochordates) and three other invertebrate taxa: hemichordates, echinoderms and Xenoturbella. The relationships between invertebrate and vertebrate deuterostomes are clearly important for understanding our own distant origins. Recent phylogenetic studies of chordate classes and a sea urchin have indicated that urochordates might be the closest invertebrate sister group of vertebrates, rather than… 
Deciphering deuterostome phylogeny: molecular, morphological and palaeontological perspectives
  • B. SwallaA. Smith
  • Biology
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2008
TLDR
Molecular phylogenies, larval morphology and the adult heart/kidney complex all support echinoderms and hemichordates as a sister grouping (Ambulacraria), andGene network data suggest that the ancestral deuterostome ancestor had an anterior–posterior body axis specified by Hox and Wnt genes, and was bilaterally symmetrical with left–right asymmetry determined by expression of nodal.
Chordate evolution and the three-phylum system
TLDR
It is proposed that an evolutionary occurrence of tadpole-type larvae is fundamental to understanding mechanisms of chordate origin and should be classified at the superphylum level, with the Chordata further subdivided into three phyla, on the basis of their distinctive characteristics.
Phylogenomic Resolution of the Hemichordate and Echinoderm Clade
Hemichordate genomes and deuterostome origins
TLDR
The draft genome sequences of two acorn worms are reported, identifying shared traits that were probably inherited from the last common deuterostome ancestor, and exploring evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates.
Hemichordate genomes and deuterostome origins
TLDR
This work reports the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava, and identifies shared traits that were probably inherited from the last common deuterostome ancestor, and explores evolutionary trajectories leading to hemichordates, echinoderms and chordates.
Crinoidea Echinoidea Holothuroidea Asteroidea Ophiuroidea Pterobranchia Ptychoderidae Xenoturbellida Cephalochordata Vertebrata Harrimaniidae Appendicularia Phlebobranchia Thaliacea Aplousobranchia Stolidobranchia Molgulidae
TLDR
Molecular phylogenies, larval morphology and the adult heart/kidney complex all support echinoderms and hemichordates as a sister grouping (Ambulacraria), andGene network data suggest that the ancestral deuterostome ancestor had an anterior–posterior body axis specified by Hox and Wnt genes, and was bilaterally symmetrical with left–right asymmetry determined by expression of nodal.
Xenacoelomorph-Specific Hox Peptides: Insights into the Phylogeny of Acoels, Nemertodermatids, and Xenoturbellids
TLDR
Results from the decoded genome of the acoel Praesagittifera naikaiensis and reported xenacoelomorph Hox genes revealed that acoels share a peptide NLK(S/T)MSQ(V/I)D, which starts immediately after the homeodomain sequence of the central Hox4/5/6.
Molecular phylogeny of hemichordata, with updated status of deep-sea enteropneusts.
Acoelomorph flatworms are deuterostomes related to Xenoturbella
TLDR
This phylogeny makes sense of the shared characteristics of Xenoturbellida and Acoelomorpha, and implies the loss of various deuterostome characters in the Xenobiology including coelomic cavities, through gut and gill slits.
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