Editing Vertebrate (section)

== Diversity ==

=== <!--Extant-->Species by group ===<!--balance subheadings, i.e. the chapter has 2 sections of which this is one-->

Described and extant vertebrate species are split roughly evenly but non-phylogenetically between non-tetrapod "fish" and tetrapods. The following table lists the number of described [[Extant taxa|extant]] species for each vertebrate [[Class (biology)|class]] as estimated in the [[IUCN Red List of Threatened Species]], 2014.3.<ref name=IUCN1014>The World Conservation Union. 2014. ''[[IUCN Red List of Threatened Species]]'', 2014.3. Summary Statistics for Globally Threatened Species. [http://cmsdocs.s3.amazonaws.com/summarystats/2014_3_Summary_Stats_Page_Documents/2014_3_RL_Stats_Table_1.pdf Table 1: Numbers of threatened species by major groups of organisms (1996–2014)].</ref> Paraphyletic groups are shown in quotation marks.

{|class="wikitable"
|-
! colspan=3 |Vertebrate groups
! Image
! Class
! Estimated number of<br/>described species<ref name=IUCN1014/><ref>{{cite book |last=Nelson |first=Joseph S. |title=Fishes of the World |year=2016 |publisher=[[John Wiley & Sons]] |isbn=978-1-118-34233-6 |pages=20, 23, 40, 102, 241}}</ref>
! Group<br/>totals<ref name=IUCN1014/>
|-
! rowspan=6 style="background:rgb(120,120,185)" |[[Anamniote|<span style="color:white;">Anamniote</span>]]<br/><br/><span style="color:white;"><small>lack<br/>[[amniotic membrane|<span style="color:white;">amniotic<br />membrane</span>]]<br/>so need to<br/>reproduce<br/>in water</small></span>
! rowspan=2 style="background:green" |[[Jawless vertebrates|<span style="color:white;">Jawless</span>]]
! rowspan=5 style="background:rgb(130,130,130)" |[[Fish|<span style="color:white;">"Fish"<!--paraphyletic--></span>]]
|[[File:Eptatretus polytrema.jpg|70px]] 
|align=center |[[Myxini]]<br/><small>(hagfish)</small>
|align=center |78
|align=center rowspan=5 |>32,900
|-
|align=center |[[File:Eudontomyzon danfordi Tiszai ingola.jpg|70px]]
|align=center |[[Hyperoartia]]<br/><small>(lampreys)</small>
|align=center |40
|-
! rowspan=7 style="background:blue" |[[Jawed vertebrates|<span style="color:white;">Jawed</span>]]
|align=center |[[File:Shark fish chondrichthyes.jpg|70px]]
|align=center |[[Chondrichthyes]]
|align=center |>1,100
|-
|align=center |[[File:Carassius wild golden fish 2013 G1.jpg|70px]] 
|align=center |[[Actinopterygii]]
|align=center |>32,000
|-
|align=center |[[File:Coelacanth-bgiu.png|70px]]
|align=center |"[[Sarcopterygii]]"<!--paraphyletic without tetrapods-->
|align=center |8
|-
! rowspan=4 style="background:rgb(130,130,130)" |[[Tetrapod|<span style="color:white;">Tetrapods</span>]]
|align=center |[[File:Lithobates pipiens.jpg|70px]]
|align=center |[[amphibian|Amphibia]]
|align=center |7,302
|rowspan=4 align=center |33,278
|-
! rowspan="3" |[[Amniote|<span style="color:gray;">Amniote</span>]]<br/><br/><span style="color:gray;"><small>have<br />[[amniotic membrane|<span style="color:gray;">amniotic<br />membrane</span>]]<br />adapted to<br/>reproducing<br />on land</small></span>
|align=center  |[[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Morenia ocellata).jpg|70px]]
|align=center |"[[reptile|Reptilia]]"<!--paraphyletic-->
|align=center |10,711
|-
|align=center |[[File:Bruno Liljefors - Hare studies 1885 white background.jpg|60px]]
|align=center |[[Mammal]]ia
|align=center |5,513
|-
|[[File:Cuvier-97-Canard colvert.jpg|70px]]
|align=center |[[bird|Aves]]
<small>(birds)</small>
|align=center |10,425
|-
|colspan=6 align=right |'''Total described species'''
|align=center |'''66,178'''
|}

The IUCN estimates that 1,305,075 [[Invertebrate#Number of extant species|extant invertebrate species]] have been described,<ref name=IUCN1014 /> which means that less than 5% of the [[Animal#Number of extant species|described animal species]] in the world are vertebrates.<ref name="Zhang2013">{{cite journal |last=Zhang |first=Zhi-Qiang |title=Animal biodiversity: An update of classification and diversity in 2013. In: Zhang, Z.-Q. (Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013) |journal=[[Zootaxa]] |volume=3703 |issue=1 |date=30 August 2013 |doi=10.11646/zootaxa.3703.1.3 |url=https://biotaxa.org/Zootaxa/article/download/zootaxa.3703.1.3/4273 |page=5 |access-date=2 March 2018 |archive-url=https://web.archive.org/web/20190424154926/https://biotaxa.org/Zootaxa/article/download/zootaxa.3703.1.3/4273 |archive-date=24 April 2019 |url-status=live |doi-access=free }}</ref>

=== Population trends ===

The [[Living Planet Index]], following 16,704 populations of 4,005 species of vertebrates, shows a decline of 60% between 1970 and 2014.<ref>{{Cite web |title=Living Planet Report 2018 |url=https://wwf.panda.org/knowledge_hub/all_publications/living_planet_report_2018/ |website=wwf.panda.org |access-date=2020-05-21}}</ref> Since 1970, freshwater species declined 83%, and tropical populations in South and Central America declined 89%.<ref name=":0">{{Cite book |url=https://s3.amazonaws.com/wwfassets/downloads/lpr2018_full_report_spreads.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://s3.amazonaws.com/wwfassets/downloads/lpr2018_full_report_spreads.pdf |archive-date=2022-10-09 |url-status=live |title=Living Planet Report – 2018: Aiming Higher |year=2018 |isbn=978-2-940529-90-2 |last1=Grooten |first1=M. |last2=Almond |first2=R. E. A. |publisher=[[World Wide Fund for Nature]] }}</ref> The authors note that "An average trend in population change is not an average of total numbers of animals lost."<ref name=":0" /> According to [[World Wide Fund for Nature |WWF]], this could lead to a sixth [[Extinction event |major extinction event]].<ref>{{Cite magazine |title=WWF Finds Human Activity Is Decimating Wildlife Populations |url=https://time.com/5438605/human-activity-wildlife-populations-wwf-report/ |magazine=Time |access-date=2020-05-21}}</ref> The five main causes of [[biodiversity loss]] are [[land-use change]], [[overexploitation]] of [[natural resource]]s, [[climate change]], [[pollution]] and [[invasive species]].<ref>{{Cite book |author=[[IPBES]] |date=2019-11-25 |title=Summary for policymakers of the global assessment report on biodiversity and ecosystem services |editor1=S. Diaz |editor2=J. Settele |editor3=E.S. Brondízio |editor4=H.T. Ngo |editor5=M. Guèze |editor6=J. Agard |editor7=A. Arneth |editor8=P. Balvanera |editor9=K.A. Brauman |editor10=S.H.M. Butchart |editor11=K.M.A. Chan |editor12=L.A. Garibaldi |editor13=K. Ichii |editor14=J. Liu |editor15=S.M. Subramanian |editor16=G.F. Midgley |editor17=P. Miloslavich |editor18=Z. Molnár |editor19=D. Obura |editor20=A. Pfaff |editor21=S. Polasky |editor22=A. Purvis |editor23=J. Razzaque |editor24=B. Reyers |editor25=R. Roy Chowdhury |editor26=Y.J. Shin |editor27=I.J. Visseren-Hamakers |editor28=K.J. Willis |editor29=C.N. Zay |display-editors=5 |publisher=IPBES Secretariat |location=Bonn |pages=1–56 |url=https://zenodo.org/record/3553579 |doi=10.5281/zenodo.3553579}}</ref>