Xenoturbella is a genus of Bilaterian animals; it is a marine worm. Its taxonomic position has been considered enigmatic since its discovery in 1949, but a 2003DNA study has positioned it as a primitive deuterostome outside of the established phyla. When treated as a higher-level taxon, Xenturbella is called Xenoturbellida. See genus (mathematics) for the use of the term in mathematics. ... Superphyla Protostomia Deuterostomia The Bilateria is a branch of Metazoa. ... WORM means Write Once, Read Many. ... 1949 is a common year starting on Saturday. ... 2003 is a common year starting on Wednesday of the Gregorian calendar. ... Space-filling model of a section of DNA molecule Deoxyribonucleic acid (DNA) or deoxyribose nucleic acid is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and many viruses). ... Phyla Echinodermata Hemichordata Chordata Chaetognatha Deuterostomes (taxonomic term: Deuterostomia; from the Greek: other mouth) are a taxon of animals. ...
Xenoturbella has a very simple body body plan: it has no brain, no gut, no gonads, or any other defined organs; it has cilia and a diffuse nervous system. The animal is up to 4 cm long, and has been found only in the Baltic Sea. The Baltic Sea is located in Northern Europe, bounded by the Scandinavian Peninsula, the mainlands of Northern Europe, Eastern Europe, Central Europe, and the Danish islands. ...
Genus Xenoturbella has two species:
Xenoturbella bocki
Xenoturbella westbladi
Bibliography
S. J. Bourlat, C. Nielsen, A. E. Lockyer, D. Timothy, J. Littlewood, M. J. Telford (2003). "Xenoturbella is a deuterostome that eats molluscs". Nature, 424, 925-928. [1]
Earlier it was suspected to be closely related to molluscs, but it turned out that the DNA test was contaminated with DNA from its food, which happened to be molluscs.
Xenoturbella has a very simple body plan: it has no brain, no gut, no gonads, or any other defined organs; it has cilia and a diffuse nervous system.
Xenoturbella is a completely unassuming little blob that seems to want nothing more in life than to wallow in the mud of the North Sea.
So Xenoturbella was for the most part effectively swept under the rug until 1997, when two studies announced that it was a mollusk.
Reisinger had suggested in 1960 that Xenoturbella might be derived from a neotenous deuterostome larva based on features of the nervous system, the enteropneust-like epidermis and the spermatozoa.
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