iDeuterostomes Fossil range: Late Ediacaran - Recent
A Sea cucumber
Scientific classification
Kingdom: Animalia Subkingdom: Eumetazoa (unranked) Bilateria Superphylum: Deuterostomia Grobben, 1908
Phyla
Echinodermata Hemichordata Chordata Xenoturbellida Chaetognatha (uncertain) Vetulicolia †

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. The Ediacaran Period is the last geological period of the Neoproterozoic Era, just before the Cambrian. ... Sea Cucumber, photography by Jacinta Richardson and Paul Fenwick. ... // ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Bryozoa Entoprocta Brachiopoda... Phyla Subkingdom Parazoa Porifera (sponges) Subkingdom Agnotozoa Placozoa Orthonectida Rhombozoa Subkingdom Metazoa Radiata Cnidaria Ctenophora - Comb jellies Bilateria Protostomia Acoelomorpha Platyhelminthes - Flatworms Nemertina - Ribbon worms Gastrotricha Gnathostomulida - Jawed worms Micrognathozoa Rotifera - Rotifers Acanthocephala Priapulida Kinorhyncha Loricifera Entoprocta Nematoda - Roundworms Nematomorpha - Horsehair worms Cycliophora Mollusca - Mollusks Sipuncula - Peanut worms Annelida - Segmented... Illustration of the different types of symmetry of Life Forms On Earth. ... 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. ... Classes Asteroidea Blastoidea (extinct) Concentricycloidea Crinoidea Echinoidea Holothuroidea Ophiuroidea This article or section does not cite its references or sources. ... Classes Enterepneusta Pterobranchia Planctosphaeroidea Hemichordata is a phylum of worm-shaped marine deuterostome animals, generally considered the sister group of our own, the chordates. ... {{{subdivision_ranks}}} See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Xenoturbella is a genus of Bilaterian animals; it is a marine worm. ... Classes Archisagittoidea Sagittoidea Chaetognatha is a phylum of predatory marine worms that are a major component of plankton worldwide. ... Vetulicolia are primitive deuterostomes from the very early Cambrian of China. ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Bryozoa Entoprocta Brachiopoda... A taxon (plural taxa), or taxonomic unit, is a grouping of organisms (named or unnamed). ... Illustration of the different types of symmetry of Life Forms On Earth. ... Phyla Subkingdom Parazoa Porifera (sponges) Subkingdom Agnotozoa Placozoa Orthonectida Rhombozoa Subkingdom Metazoa Radiata Cnidaria Ctenophora - Comb jellies Bilateria Protostomia Acoelomorpha Platyhelminthes - Flatworms Nemertina - Ribbon worms Gastrotricha Gnathostomulida - Jawed worms Micrognathozoa Rotifera - Rotifers Acanthocephala Priapulida Kinorhyncha Loricifera Entoprocta Nematoda - Roundworms Nematomorpha - Horsehair worms Cycliophora Mollusca - Mollusks Sipuncula - Peanut worms Annelida - Segmented... Groups Protostomes (from the Greek: first the mouth) are a taxon of animals. ... Embryogenesis is the process by which the embryo is formed and develops. ... A blastopore is an opening into the archenteron during the embryonic stages of an organism. ... Female Human Anatomy Male Human Anatomy Anal redirects here. ... Look up Mouth in Wiktionary, the free dictionary. ...

There are four living phyla of deuterostomes:

• Phylum Chordata (vertebrates and their kin)
• Phylum Echinodermata (starfishes, sea urchins, sea cucumbers, etc.)
• Phylum Hemichordata (acorn worms and possibly graptolites)
• Phylum Xenoturbellida (2 species of worm-like animals from the Baltic Sea)

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, Hemichordata, and Xenoturbellida. Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Classes and Clades See below Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns. ... Classes Asteroidea Concentricycloidea Crinoidea Echinoidea Holothuroidea Ophiuroidea Echinoderms (Echinodermata) is a phylum of marine animals found in the ocean at all depths. ... NON TECHNICAL AND OF LOW INTELLIGENCE COMPUTER USER CALLING TECH SUPPORT. SEE S.E.C.S. ALSO This page is a candidate for speedy deletion. ... Subclasses Euechinoidea Superorder Atelostomata Order Cassiduloida Order Spatangoida (heart urchins) Superorder Diadematacea Order Diadematoida Order Echinothurioida Order Pedinoida Superorder Echinacea Order Arbacioida Order Echinoida Order Phymosomatoida Order Salenioida Order Temnopleuroida Superorder Gnathostomata Order Clypeasteroida (sand dollars) Order Holectypoida Perischoechinoidea Order Cidaroida (pencil urchins) Sea urchins are spiny sea creatures of... // ... Classes Enterepneusta Pterobranchia Planctosphaeroidea Hemichordata is a phylum of worm-shaped marine deuterostome animals, generally considered the sister group of our own, the chordates. ... Graptolites (Graptolithina) are fossil colonial animals known chiefly from the Upper Cambrian through the Mississippian (Lower Carboniferous). ... Species  Westblad, 1949  Israelsson, 1999 Xenoturbella is a genus of bilaterian animals; it is a marine worm. ... The Baltic Sea is located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. ... Classes Archisagittoidea Sagittoidea Chaetognatha is a phylum of predatory marine worms that are a major component of plankton worldwide. ... Vetulicolia are primitive deuterostomes from the very early Cambrian of China. ...

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. Cleavage is indeterminate - 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. Blastulation. ... Radial cleavage is a cleavage pattern characteristic of vertebrates and echinoderms, in which the spindle axes are parallel or at right angles to the polar axis of the oocyte. ... The lophophorates are animals united by a presence of a lophophore, a fan of cilia surrounding the mouth. ...

In deuterostomes the mesoderm forms as evaginations of the developed gut that pinch off, forming the coelom. This is called enterocoely. It has been suggested that organogenesis be merged into this article or section. ... By the broadest definition, a body cavity is any fluid filled space in a multicellular organism. ...

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 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. Gill slits are gills with individual openings rather than a outer cover. ... Classes Ascidiacea Thaliacea Appendicularia Sorberacea Urochordata (sometimes known as tunicata and commonly called urochordates, tunicates, sea squirts or cunji) is the subphylum of saclike filter feeders with input and output siphons. ... Vetulicolia are primitive deuterostomes from the very early Cambrian of China. ...

External links

Wikispecies has information related to:

Deuterostomia

• UCMP-Deuterostomes