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Information about Deuterostomia

Deuterostomes
Fossil range: Late Ediacaran - Recent
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A Sea cucumber

Scientific classification
Kingdom:Animalia
Subkingdom:Eumetazoa
(unranked)Bilateria
Superphylum:Deuterostomia
Grobben, 1908
Phyla


Deuterostomes (taxonomic term: Deuterostomia; from the Greek: "second mouth") are a superphylum of animals. They are a subtaxon of the Bilateria branch of the subregnum Eumetazoa, and are opposed to the protostomes. Deuterostomes are distinguished by their embryonic development; in deuterostomes, the first opening (the blastopore) becomes the anus, while in protostomes it becomes the mouth.

There are four living phyla of deuterostomes: The phylum Chaetognatha (arrow worms) may also belong here. Extinct groups may include the phylum Vetulicolia. The term Ambulacraria is sometimes used to unite the phyla Echinodermata and Hemichordata.

In both deuterostomes and protostomes, a zygote first develops into a hollow ball of cells, called a blastula. In deuterostomes, the early divisions occur parallel or perpendicular to the polar axis. This is called radial cleavage, and also occurs in certain protostomes, such as the lophophorates. Deuterostomes display indeterminate cleavage - the cells' fates are not determined early on. Thus if the first four cells are separated, each cell is capable of forming a complete small larva, and if a cell is removed from the blastula the other cells will compensate.

In deuterostomes the mesoderm forms as evaginations of the developed gut that pinch off, forming the coelom. This is called enterocoely.

Both the Hemichordata and Chordata have gill slits, and primitive fossil echinoderms also show signs of gill slits. A hollow nerve cord is found in all chordates, even tunicates (even if it disappears in the adults). Some hemichordates also have a tubular nerve cord. In the early embryonic stage it looks like the hollow nerve cord of chordates. Because of the degenerated nervous system of echinoderms it is not possible to discern much about their ancestors in this matter, but based on different facts it is quite possible that all the present deuterostomes evolved from a common ancestor which had gill slits, a hollow nerve cord and a segmented body. It could have resembled the small group of Cambrian deuterostomes named Vetulicolia.

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Cryogenian

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Holothuroidea

Orders
  • Subclass Apodacea
  • Apodida
  • Molpadiida
  • Subclass Aspidochirotacea

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Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. Scientific classification also can be called scientific taxonomy, but should be distinguished from folk taxonomy, which lacks scientific basis.
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Eumetazoa
Butschli, 1910

subgroups
  • Placozoa
  • Radiata
  • Bilateria


Eumetazoa is a clade comprising all major animal groups except sponges.
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Bilateria
Hatschek, 1888

Subgroups
  • Deuterostomia
  • Echinodermata (20,000 species)
  • Hemichordata (71 species)
  • Chordata (63,000 species)

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Karl Grobben (sometimes written Carl Grobben) was an Austrian biologist, who was born on August 27 1854 in Brno, and died on April 13 1945 in Salzburg. He graduated from, and later worked at, the University of Vienna, chiefly on molluscs and crustaceans.
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Xenoturbellida

Family: Xenoturbellidae

Genus: Xenoturbella

Species
X. bocki  Westblad, 1949
X.
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Vetulicolia
Shu, et al. 2001

Order: Vetulicolida

Families
  • Didazoonidae
  • Vetulicolidae
Vetulicolia is an extinct phylum erected by Shu et al.
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Echinodermata
Klein, 1734

Subphyla & Classes
  • Homalozoa Gill & Caster, 1960
Homostelea
Homoiostelea
Stylophora
Ctenocystoidea Robison & Sprinkle, 1969
  • Crinozoa

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Hemichordata
Bateson, 1885

Classes
  • Enteropneusta
  • Pterobranchia
  • Planctosphaeroidea


Hemichordata is a phylum of worm-shaped marine deuterostome animals, generally considered the sister group of the echinoderms.
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Chordata
Bateson, 1885

Typical Classes

See below

Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
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For the journal, see .
A taxon (plural taxa), or taxonomic unit, is a name designating an organism or group of organisms. A taxon is assigned a rank and can be placed at a particular level in a systematic hierarchy reflecting evolutionary
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Bilateria
Hatschek, 1888

Subgroups
  • Deuterostomia
  • Echinodermata (20,000 species)
  • Hemichordata (71 species)
  • Chordata (63,000 species)

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Eumetazoa
Butschli, 1910

subgroups
  • Placozoa
  • Radiata
  • Bilateria


Eumetazoa is a clade comprising all major animal groups except sponges.
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Protostomia

Groups
  • Ecdysozoa
  • Lophotrochozoa
  • Platyzoa


Protostomes (from the Greek: mouth first) are a taxon of animals.
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Embryogenesis is the process by which the embryo is formed and develops. It starts with the fertilization of the ovum, egg, which, after fertilization, is then called a zygote.
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A blastopore is an opening into the archenteron during the embryonic stages of an organism. The distinction between protostomes and deuterostomes is based on the direction in which the mouth (stoma) develops in relation to the blastopore.
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anus (from Latin ānus "ring, anus") is the external opening of the rectum. Closure is controlled by sphincter muscles. Feces are expelled from the body through the anus during the act of defecation, which is the primary function of the anus.
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mouth, also known as the buccal cavity or the oral cavity, is the orifice through which an organism takes in food and water.

Location

In all mammals, the mouth is forward-facing in the face. Non-mammals have mouths in other locations (e.g.
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Chordata
Bateson, 1885

Typical Classes

See below

Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
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Vertebrata
Cuvier, 1812

Classes and Clades

See below
Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns.
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Echinodermata
Klein, 1734

Subphyla & Classes
  • Homalozoa Gill & Caster, 1960
Homostelea
Homoiostelea
Stylophora
Ctenocystoidea Robison & Sprinkle, 1969
  • Crinozoa

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Echinoidea
Leske, 1778

Subclasses
  • Subclass Perischoechinoidea
  • Order Cidaroida (pencil urchins)
  • Subclass Euechinoidea

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Holothuroidea

Orders
  • Subclass Apodacea
  • Apodida
  • Molpadiida
  • Subclass Aspidochirotacea

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Hemichordata
Bateson, 1885

Classes
  • Enteropneusta
  • Pterobranchia
  • Planctosphaeroidea


Hemichordata is a phylum of worm-shaped marine deuterostome animals, generally considered the sister group of the echinoderms.
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Enteropneusta

Families

Harrimaniidae
Protoglossidae
Ptychoderidae
Saxipendiidae
Spengelidae
Torquaratoridae

The Acorn worms or Enteropneusta are a hemichordate class of invertebrates.
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Graptolithina

Orders
  • Dendroidea
  • Tuboidea
  • Camaroidea
  • Crustoidea
  • Stolonoidea
  • Graptoloidea
  • Dithecoidea


Graptolites
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