Ultrastructure and formation of the body cavity lining in Phoronis muelleri (Phoronida, Lophophorata)

@article{Bartolomaeus2001UltrastructureAF,
  title={Ultrastructure and formation of the body cavity lining in Phoronis muelleri (Phoronida, Lophophorata)},
  author={Thomas Bartolomaeus},
  journal={Zoomorphology},
  year={2001},
  volume={120},
  pages={135-148}
}
Abstract Among other characteristics a trimeric coelomic compartmentation consisting of an anterior protocoel, followed by a mesocoel and a posterior metacoel is traditionally believed to substantiate the sister-group relationship between Lophophorata and Deuterostomia, together forming the Radialia. As molecular data cannot support this hypothesis a reanalysis of the coelomic cavities in Phoronida is undertaken, because corresponding coelomic compartmentation is widely accepted to support the… 

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References

SHOWING 1-10 OF 42 REFERENCES

Fine Structure of the Tentacles of Phoronis australis Haswell (Phoronida, Lophophorata)

The epidermis of the tentacles of Phoronis australis consists of six cell types: supporting cells, choanocyte-like sensory cells, both types monociliated, secretory A-cells with a mucous secretion,

The origin of the coelom in Brachiopoda and its phylogenetic significance

TLDR
Considering endodermal origin as the crucial character for enterocoely, coelom formation through proliferation of a compact, endodermally derived mesodermal cell mass in Brachiopoda is clearly identified as enterocoesly.

Function of lateral cilia in suspension feeding of lophophorates (Brachiopoda, Phoronida, Ectoprocta)

TLDR
Distribution of the feeding mechanism among phyla, clearance rates, and the lack of fusion of tentacles in brachiopods are discussed and the impingement mechanism previously suggested for lophophorates cannot account for the movements of particles observed here.

The Development of the Brachiopod Crania (Neocrania) anomala (O. F. Müller)and its Phylogenetic Significance

TLDR
Both groups have originated from a creeping ancestor with a straight gut and the ventral curving of the settling larva and the formation of both valves from dorsal epithelial areas indicate that the brachiopods have a very short ventral side as opposed to the phoronids.

The Median Tentacle of the Larva of Lingula Anatina (Brachiopoda) From Queensland, Australia

The median tentacle of the larvae of Lingula anatina has been investigated in order to obtain information about the morphological implications of its function and its relation to the paired tentacles

Ultrastructure of the basal lamina and its relationship to extracellular matrix of embryos of the starfish Pisaster ochraceus as revealed by anionic dyes

TLDR
The fact that the basal cell surfaces are often puckered outward at the points of contact suggests that this configuration might be providing a means whereby forces can be transferred from the ECM through the basal lamina to the cells.

Structure and Function of Metazoan Ciliary Bands and Their Phylogenetic Significance

TLDR
The trochaea theory predicts that Porifera and Cnidaria have only monociliate cells and lack ciliary bands used in filter-feeding, and that the gastroneuralian larvae have downstream-collecting ciliated bands with prototroch and metatroch of compound cilia on multiciliate cells.

Origin of the chordate central nervous system – and the origin of chordates

  • C. Nielsen
  • Biology
    Development Genes and Evolution
  • 1999
TLDR
Molecular evidence indicates that the protostomian ventral nerve cord plus apical brain is homologous with the vertebrates’ dorsal spinal cord plus brain, which leads to the hypothesis that the two organs evolved from the same area in the latest common bilaterian ancestor, just anterior to the blastopore.

Monophyly of brachiopods and phoronids: reconciliation of molecular evidence with Linnaean classification (the subphylum Phoroniformea nov.)

  • B. Cohen
  • Biology, Geography
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2000
Molecular phylogenetic analyses of aligned 18S rDNA gene sequences from articulate and inarticulate brachiopods representing all major extant lineages, an enhanced set of phoronids and several