<span class="mw-page-title-main">Deuterostome</span>

Deuterostome

<p><b>Deuterostomia</b> (<span class="rt-commentedText nowrap"><span class="IPA nopopups noexcerpt"><a href="/en/Help:IPA/English" title="Help:IPA/English" class="wl">/<span style="border-bottom:1px dotted"><span>ˌ</span><span>dj</span><span>uː</span><span>t</span><span>ər</span><span>ə</span><span>ˈ</span><span>s</span><span>t</span><span>oʊ</span><span>m</span><span>i</span><span>.</span><span>ə</span></span>/</a></span></span>; <abbr style="font-size:85%" about="#mwt16" typeof="mw:Transclusion mw:ExpandedAttrs" data-mw="{&quot;parts&quot;:[{&quot;template&quot;:{&quot;target&quot;:{&quot;wt&quot;:&quot;lit&quot;,&quot;href&quot;:&quot;./Template:Lit&quot;},&quot;params&quot;:{&quot;1&quot;:{&quot;wt&quot;:&quot;second mouth&quot;}},&quot;i&quot;:0}}]}">lit.</abbr><span style="white-space: nowrap;"><span> </span></span><span>'</span><span>second mouth</span><span>'</span> in <a href="/en/Ancient_Greek" title="Ancient Greek" class="wl">Greek</a>)<span class="mw-ref reference" id="cite_ref-NYT-20170130_2-0"><a href="#cite_note-NYT-20170130-2" style="counter-reset: mw-Ref 2;"><span class="mw-reflink-text">[2]</span></a></span><span class="mw-ref reference" id="cite_ref-NAT-20170130_3-0"><a href="#cite_note-NAT-20170130-3" style="counter-reset: mw-Ref 3;"><span class="mw-reflink-text">[3]</span></a></span> are animals typically characterized by their <a href="/en/Anus" title="Anus" class="wl">anus</a> forming before their <a href="/en/Mouth" title="Mouth" class="wl">mouth</a> during <a href="/en/Embryogenesis" title="Embryogenesis" class="mw-redirect wl">embryonic development</a>. The group's sister clade is <a href="/en/Protostomia" title="Protostomia" class="mw-redirect wl">Protostomia</a>, animals whose <a href="/en/Digestive_tract" title="Digestive tract" class="mw-redirect wl">digestive tract</a> development is more varied. Some examples of <b>deuterostomes</b> include <a href="/en/Vertebrate" title="Vertebrate" class="wl">vertebrates</a> (and thus humans), <a href="/en/Sea_star" title="Sea star" class="mw-redirect wl">sea stars</a>, and <a href="/en/Crinoid" title="Crinoid" class="wl">crinoids</a>.</p>

<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt1">Superphylum of bilateral animals</div>
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</span><div class='mobile-collapse'><header class="mobile-collapse-header mobile-collapse-btn"><b>Quick facts: Deuterostomes Temporal range  Earliest Cambri...</b> <span class='arrow'>▼</span></header> <table class="infobox biota mobile-collapse-element" style="text-align: left; width: 200px; font-size: 100%">
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<th colspan="2" style="text-align: center; background-color: rgb(235,235,210)" class="notheme">Deuterostomes<br><div style="font-size: 85%;">Temporal range: Earliest <a href="/en/Cambrian" title="Cambrian" class="wl">Cambrian</a> (<a href="/en/Fortunian" title="Fortunian" class="wl">Fortunian</a>) – <a href="/en/Holocene" title="Holocene" class="wl">Present</a> <span class="noprint"><span style="display:inline-block;">540–0<span>&nbsp;</span><a href="/en/Megaannum" title="Megaannum" class="mw-redirect wl">Ma</a></span> <div id="Timeline-row" style="margin: 4px auto 0; clear:both; width:220px; padding:0px; height:18px; overflow:visible; white-space:nowrap; border:1px #666; border-style:solid none; position:relative; z-index:0; font-size:97%;">
<div style="position:absolute; height:100%; left:0px; width:207.23076923077px; padding-left:5px; text-align:left; background-color:rgb(254,217,106); background-image: linear-gradient(to right, rgba(255,255,255,1), rgba(254,217,106,1) 15%, rgba(254,217,106,1));" class="notheme"><a href="/en/Precambrian" title="Precambrian" class="wl">PreꞒ</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(127,160,86); left:37.636923076923px; width:18.073846153846px;" class="notheme"><a href="/en/Cambrian" title="Cambrian" class="wl">Ꞓ</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(0,146,112); left:55.710769230769px; width:14.08px;" class="notheme"><a href="/en/Ordovician" title="Ordovician" class="wl">O</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(179,225,182); left:69.790769230769px; width:8.3261538461539px;" class="notheme"><a href="/en/Silurian" title="Silurian" class="wl">S</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(203,140,55); left:78.116923076923px; width:20.409230769231px;" class="notheme"><a href="/en/Devonian" title="Devonian" class="wl">D</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(103,165,153); left:98.526153846154px; width:20.307692307692px;" class="notheme"><a href="/en/Carboniferous" title="Carboniferous" class="wl">C</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(240,64,40); left:118.83384615385px; width:15.907015384615px;" class="notheme"><a href="/en/Permian" title="Permian" class="wl">P</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(129,43,146); left:134.74086153846px; width:17.092984615385px;" class="notheme"><a href="/en/Triassic" title="Triassic" class="wl">T</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(52,178,201); left:151.83384615385px; width:19.089230769231px;" class="notheme"><a href="/en/Jurassic" title="Jurassic" class="wl">J</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(127,198,78); left:170.92307692308px; width:26.738461538462px;" class="notheme"><a href="/en/Cretaceous" title="Cretaceous" class="wl">K</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(253,154,82); left:197.66153846154px; width:14.543692307692px;" class="notheme"><a href="/en/Paleogene" title="Paleogene" class="wl">Pg</a></div>
<div style="position:absolute; height:100%; text-align:center; background-color:rgb(255,230,25); left:212.20523076923px; width:6.9215384615385px;" class="notheme"><a href="/en/Neogene" title="Neogene" class="wl">N</a></div>
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<div style="position:absolute; height:8px; left:37.230769230769px; width:182.76923076923px; background-color:#360; opacity:1; " class="notheme"></div>
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<td colspan="2" style="text-align: center"><span class="mw-default-size"><a href="/en/File:Deuterostomia.jpg" class="mw-file-description image media-thumb" data-hash="File:Deuterostomia.jpg"><img loading="lazy" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Deuterostomia.jpg/220px-Deuterostomia.jpg" decoding="async" data-file-width="1000" data-file-height="1000" data-file-type="bitmap" height="220" width="220" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Deuterostomia.jpg/330px-Deuterostomia.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Deuterostomia.jpg/440px-Deuterostomia.jpg 2x" alt="Deuterostomia.jpg"></a></span></td></tr>
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<td colspan="2" style="text-align: center; font-size: 88%">Examples of deuterostomes</td></tr>


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<th colspan="2" style="min-width:15em; text-align: center; background-color: rgb(235,235,210)" class="notheme"><a href="/en/Taxonomy_(biology)" title="Taxonomy (biology)" class="wl">Scientific classification</a> <span class="plainlinks" style="font-size:smaller; float:right; padding-right:0.4em; margin-left:-3em;"><span class="mw-default-size"><a href="/en/Template:Taxonomy/Deuterostomia" title="e" class="image wl"><img loading="lazy"alt="e" src="//upload.wikimedia.org/wikipedia/commons/7/74/Red_Pencil_Icon.png" decoding="async" data-file-width="16" data-file-height="16" data-file-type="bitmap" height="16" width="16"></a></span></span></th></tr>
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<td>Kingdom:</td>
<td><a href="/en/Animal" title="Animal" class="wl">Animalia</a></td></tr>
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<td>Subkingdom:</td>
<td><a href="/en/Eumetazoa" title="Eumetazoa" class="wl">Eumetazoa</a></td></tr>
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<td><i>Clade</i>:</td>
<td><a href="/en/ParaHoxozoa" title="ParaHoxozoa" class="wl">ParaHoxozoa</a></td></tr>
<tr>
<td><i>Clade</i>:</td>
<td><a href="/en/Bilateria" title="Bilateria" class="wl">Bilateria</a></td></tr>
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<td><i>Clade</i>:</td>
<td><a href="/en/Nephrozoa" title="Nephrozoa" class="wl">Nephrozoa</a></td></tr>
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<td>Superphylum:</td>
<td><a href="/en/Deuterostome" title="Deuterostome" class="wl">Deuterostomia</a><br><small><a href="/en/Karl_Grobben" title="Karl Grobben" class="wl">Grobben</a>, 1908</small></td></tr>



































































































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<tr>
<th colspan="2" style="text-align: center; background-color: rgb(235,235,210)" class="notheme">Clades</th></tr>
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<td colspan="2" style="text-align: left">
<ul><li><a href="/en/Chordata" title="Chordata" class="mw-redirect wl">Chordata</a></li>
<li><a href="/en/Saccorhytus" title="Saccorhytus" class="wl">Saccorhytida</a>? <a href="/en/Extinction" title="Extinction" class="wl">†</a></li>
<li><a href="/en/Vetulicolia" title="Vetulicolia" class="wl">Vetulicolia</a><a href="/en/Extinction" title="Extinction" class="wl">†</a><span class="mw-ref reference" id="cite_ref-1"><a href="#cite_note-1" style="counter-reset: mw-Ref 1;"><span class="mw-reflink-text">[1]</span></a></span></li>
<li><a href="/en/Ambulacraria" title="Ambulacraria" class="wl">Ambulacraria</a>
<ul><li><a href="/en/Hemichordata" title="Hemichordata" class="mw-redirect wl">Hemichordata</a></li>
<li><a href="/en/Echinodermata" title="Echinodermata" class="mw-redirect wl">Echinodermata</a></li>
<li><a href="/en/Cambroernida" title="Cambroernida" class="mw-redirect wl">Cambroernida</a>†</li></ul></li></ul></td></tr>

















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<p>In deuterostomy, the developing embryo's first opening (the <a href="/en/Blastopore" title="Blastopore" class="mw-redirect wl">blastopore</a>) becomes the anus, while the mouth is formed at a different site later on. This was initially the group's distinguishing characteristic, but deuterostomy has since been discovered among protostomes as well.<span class="mw-ref reference" id="cite_ref-4"><a href="#cite_note-4" style="counter-reset: mw-Ref 4;"><span class="mw-reflink-text">[4]</span></a></span> This group is also known as <b>enterocoelomates</b>, because their <a href="/en/Coelom" title="Coelom" class="wl">coelom</a> develops through <a href="/en/Enterocoely" title="Enterocoely" class="wl">enterocoely</a>.</p>

<p>The three major clades of deuterostomes are <a href="/en/Chordata" title="Chordata" class="mw-redirect wl">Chordata</a> (e.g. <a href="/en/Vertebrate" title="Vertebrate" class="wl">vertebrates</a>), <a href="/en/Echinodermata" title="Echinodermata" class="mw-redirect wl">Echinodermata</a> (e.g. <a href="/en/Starfish" title="Starfish" class="wl">starfish</a>), and <a href="/en/Hemichordata" title="Hemichordata" class="mw-redirect wl">Hemichordata</a> (e.g. <a href="/en/Acorn_worm" title="Acorn worm" class="wl">acorn worms</a>). Together with Protostomia and their out-group <a href="/en/Xenacoelomorpha" title="Xenacoelomorpha" class="wl">Xenacoelomorpha</a>, these compose the <a href="/en/Bilateria" title="Bilateria" class="wl">Bilateria</a>, animals with bilateral symmetry and three germ layers.</p>



Deuterostomia  are animals typically characterized by their anus forming before their mouth during embryonic development. The group's sister clade is Protostomia, animals whose digestive tract development is more varied. Some examples of deuterostomes include vertebrates , sea stars, and crinoids. In deuterostomy, the developing embryo's first opening becomes the anus, while the mouth is formed at a different site later on. This was initially the group's distinguishing characteristic, but deuterostomy has since been discovered among protostomes as well. This group is also known as enterocoelomates, because their coelom develops through enterocoely. 