Editing Crocodile (section)

==Taxonomy and phylogeny==
{{See also|List of crocodilians}}
Crocodylidae was named as a [[family (biology)|family]] by [[Georges Cuvier]] in 1807. It belongs to the larger [[Superfamily (taxonomy)|superfamily]] [[Crocodyloidea]], which also includes additional extinct crocodile relatives. These all belong to the [[Order (biology)|order]] [[Crocodilia]], which also includes [[alligators]] and [[gharials]].

Although crocodiles, alligators, and the gharial are similar in appearance, they belong to separate [[family (biology)|biological families]]. The gharial, with its narrow [[snout]], is easier to distinguish, while [[Morphology (biology)|morphological]] differences are more difficult to spot in crocodiles and alligators. The most obvious external differences are visible in the head, with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators and caimans. Another obvious trait is that the upper and lower jaws of the crocodiles are the same width, and the [[teeth]] in the lower jaw fall along the edge or outside the upper jaw when the mouth is closed; therefore, all teeth are visible, unlike an alligator, which possesses in the upper jaw small depressions into which the lower teeth fit. Also, when the crocodile's mouth is closed, the large fourth tooth in the lower jaw fits into a constriction in the upper jaw. For hard-to-distinguish specimens, the protruding tooth is the most reliable feature to define the [[species]]' [[family (biology)|family]].<ref>{{cite web |url=http://www.flmnh.ufl.edu/cnhc/cbd-faq-q1.htm |title=Crocodilian Biology Database – FAQ – What's the difference between a crocodile and an alligator |publisher=Flmnh.ufl.edu |access-date=5 April 2009}}</ref> Crocodiles have more [[webbing]] on the toes of the hind [[Foot|feet]] and can better tolerate [[saline water|saltwater]] due to specialized [[salt gland]]s for filtering out salt, which are present, but non-functioning, in alligators. Another trait that separates crocodiles from other crocodilians is their much higher levels of [[aggression]].<ref name="Guggisberg">{{cite book | author = Guggisberg, C. A. W. | title = Crocodiles: Their Natural History, Folklore, and Conservation| year = 1972 | page = 195 | isbn = 978-0-7153-5272-4 | publisher = David & Charles | location = Newton Abbot, England}}</ref>

Crocodylidae is [[cladistic]]ally defined as a [[crown group]] composed of the [[last common ancestor]] of the [[Nile crocodile]] (''Crocodylus niloticus''), the [[Dwarf crocodile]] (''Osteolaemus tetraspis''), and all of its descendants.<ref name="Rio2021">{{cite journal |last1=Rio |first1=Jonathan P. |last2=Mannion |first2=Philip D. |date=6 September 2021 |title=Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem |journal=[[PeerJ]] |volume=9 |pages=e12094 |doi=10.7717/peerj.12094 |pmid=34567843 |pmc=8428266 |doi-access=free}}</ref> It contains two [[subfamily (biology)|subfamilies]]: [[Crocodylinae]] and [[Osteolaeminae]].<ref name="Hekkala2021">{{Cite journal|last1=Hekkala |first1=E. |last2=Gatesy |first2=J. |last3=Narechania |first3=A. |last4=Meredith |first4=R. |last5=Russello |first5=M. |last6=Aardema |first6=M. L. |last7=Jensen |first7=E. |last8=Montanari |first8=S. |last9=Brochu |first9=C. |last10=Norell |first10=M. |last11=Amato |first11=G. |date=27 April 2021 |title=Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus |journal=Communications Biology |language=en |volume=4 |issue=1 |page=505 |doi=10.1038/s42003-021-02017-0 |pmid=33907305 |pmc=8079395 |issn=2399-3642 |doi-access=free}}</ref>  Crocodylinae contains 13-14 living species, as well as 6 [[extinct]] species.  Osteolaeminae was named by Christopher Brochu in 2003 as a subfamily of Crocodylidae separate from Crocodylinae,<ref name=C.thorbjarnarsoni>{{Cite journal | last1 = Brochu | first1 = C. A. | last2 = Storrs | first2 = G. W. | doi = 10.1080/02724634.2012.652324 | title = A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity of ''Crocodylus'' in Africa | journal = Journal of Vertebrate Paleontology | volume = 32 | issue = 3 | pages = 587–602 | year = 2012 | bibcode = 2012JVPal..32..587B | s2cid = 85103427 }}</ref> and contains the two [[extant taxon|extant]] [[genus|genera]] ''[[Osteolaemus]]'' and ''[[Mecistops]]'', along with several extinct genera.  The number of extant species within Osteolaeminae is currently in question.<ref name="Eaton"/>
[[File:Crocfarm.jpg|thumb|[[Crocodile farm]]ing in Australia]]
[[File:Crocadiles.jpg|right|thumb|Crocodiles in [[Costa Rica]]]]
[[File:Crocodylus acutus mexico 01.jpg|thumb|right|[[American crocodile]] at [[La Manzanilla, Jalisco, Mexico]]]]
[[File:Voay robustus.JPG|thumb|A skull of the extinct ''[[Voay robustus]]'']]
* '''Subfamily [[Crocodylinae]]'''
** Genus ''[[Crocodylus]]''
***''[[Crocodylus acutus]]'', [[American crocodile]]
***''[[Crocodylus halli]]'', [[Hall's New Guinea crocodile]] found South of the [[New Guinea Highlands]]<ref name="MurrayRussoZorrillaMcMahan2019">{{cite journal | last1 = Murray | first1 = Christopher M. | last2 = Russo | first2 = Peter | last3 = Zorrilla | first3 = Alexander | last4 = McMahan | first4 = Caleb D. | year = 2019 | title = Divergent Morphology among Populations of the New Guinea Crocodile, Crocodylus novaeguineae (Schmidt, 1928) Diagnosis of An Independent Lineage and Description of A New Species. | journal = Copeia | volume = 107 | issue = 3| pages = 517–523 | doi = 10.1643/CG-19-240 | doi-access = free }}</ref>
***''[[Crocodylus intermedius]]'', [[Orinoco crocodile]]
***''[[Crocodylus johnsoni]]'', [[freshwater crocodile]], or Johnstone's crocodile
***''[[Crocodylus mindorensis]]'', [[Philippine crocodile]]
***''[[Crocodylus moreletii]]'', [[Morelet's crocodile]] or Mexican crocodile
***''[[Crocodylus niloticus]]'', [[Nile crocodile]] or African crocodile (the subspecies found in Madagascar is sometimes called the black crocodile)
***''[[Crocodylus novaeguineae]]'', [[New Guinea crocodile]] found North of the [[New Guinea Highlands]]
***''[[Crocodylus palustris]]'', [[Mugger Crocodile|mugger]], marsh or Indian crocodile
***''[[Crocodylus porosus]]'', [[saltwater crocodile]] or estuarine crocodile
****''[[Crocodylus raninus]]'', the [[Borneo crocodile]], is currently considered to be a synonym of ''Crocodylus porosus''; whether or not it is a distinct species remains unclear.<ref>{{Cite web|url=http://reptile-database.reptarium.cz/species?genus=Crocodylus&species=raninus|title = Species &#124; the Reptile Database}}</ref>
***''[[Crocodylus rhombifer]]'', [[Cuban crocodile]]
***''[[Crocodylus siamensis]]'', [[Siamese crocodile]] (may be extinct in the wild)
***''[[Crocodylus suchus]]'', [[West African crocodile]], desert or sacred crocodile
***''[[Crocodylus anthropophagus]]''{{extinct}}
***''[[Crocodylus checchiai]]''{{extinct}}
***''[[Crocodylus falconensis]]''{{extinct}}
***''[[Crocodylus palaeindicus]]''{{extinct}}
***''[[Crocodylus thorbjarnarsoni]]''{{extinct}}
** Genus ''[[Voay]]''{{extinct}}
***''[[Voay robustus]]''{{extinct}} (formerly ''Crocodylus robustus'')
* '''Subfamily [[Osteolaeminae]]'''
** Genus ''[[Osteolaemus]]''
*** ''[[Osteolaemus tetraspis]]'', [[dwarf crocodile]] (There has been controversy as to whether or not this is actually two species; recent (2010) DNA analysis indicate three distinct species: ''O. tetraspis'', ''O. osborni'' and a third, currently unnamed.)
** Genus ''[[Mecistops]]''
***''[[Mecistops cataphractus]]'' [[West African slender-snouted crocodile]]
*** ''[[Mecistops leptorhynchus]]'' [[Central African slender-snouted crocodile]]
** Genus ''[[Brochuchus]]''{{extinct}}
*** ''[[Brochuchus pigotti]]''{{extinct}} (formerly ''Crocodylus pigotti'')
*** ''[[Brochuchus parvidens]]''{{extinct}}
** Genus ''[[Euthecodon]]''{{extinct}}
*** ''[[Euthecodon nitriae]]''{{extinct}}
*** ''[[Euthecodon brumpti]]''{{extinct}}
*** ''[[Euthecodon arambourgi]]''{{extinct}}
** Genus ''[[Rimasuchus]]''{{extinct}}
*** ''[[Rimasuchus lloydi]]''{{extinct}} (formerly ''Crocodylus lloydi'')

===Phylogeny===
Recent molecular studies using [[DNA sequencing]] have shown crocodiles to be more closely related to the [[gavialid]]s rather than to [[alligator]]s, contrary to prior theories based on [[morphology (biology)|morphological]] studies alone.<ref name="Harshman2003">{{cite journal |pmid=12775527 |year=2003 |last1=Harshman |first1=J. |title=True and false gharials: A nuclear gene phylogeny of crocodylia |journal=Systematic Biology |volume=52|issue=3|pages=386–402|last2=Huddleston|first2=C. J. |last3=Bollback |first3=J. P. |last4=Parsons|first4=T. J.|last5=Braun|first5=M. J.|doi=10.1080/10635150309323 |url=http://si-pddr.si.edu/bitstream/handle/10088/6275/2003C_Harshman_et_al.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://si-pddr.si.edu/bitstream/handle/10088/6275/2003C_Harshman_et_al.pdf |archive-date=2022-10-09 |url-status=live|doi-access=free }}</ref><ref name="Gatesy2008">{{cite journal|last1=Gatesy |first1=J. |last2=Amato |first2=G. |year=2008 |title=The rapid accumulation of consistent molecular support for intergeneric crocodylian relationships |journal=[[Molecular Phylogenetics and Evolution]]|volume=48 |issue=3 |pages=1232–1237 |doi=10.1016/j.ympev.2008.02.009|pmid=18372192|bibcode=2008MolPE..48.1232G }}</ref><ref name=bite>{{cite journal| author=Erickson, G. M.| author2=Gignac, P. M.| author3=Steppan, S. J.| author4=Lappin, A. K.| author5=Vliet, K. A.| author6=Brueggen, J. A.| author7=Inouye, B. D.| author8=Kledzik, D.| author9=Webb, G. J. W. | year=2012 | title=Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation | journal=PLOS ONE | volume=7 |issue=3 |page=e31781 |doi=10.1371/journal.pone.0031781|editor1-last=Claessens|editor1-first=Leon|bibcode = 2012PLoSO...731781E | pmid=22431965 | pmc=3303775| doi-access=free}}</ref><ref name="LeeYates2018">{{cite journal | author=Michael S. Y. Lee |author2=Adam M. Yates |date=27 June 2018 |title=Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil |journal=[[Proceedings of the Royal Society B]] |volume=285 |issue=1881 |doi=10.1098/rspb.2018.1071 |pmid=30051855 |pmc=6030529 |doi-access=free}}</ref><ref name="Hekkala2021"/>

Below is a [[cladogram]] showing the relationships of the major [[extant taxon|extant]] crocodile groups based on molecular studies, excluding separate extinct taxa:
{{clade| style=font-size:85%;line-height:85%
|label1='''[[Crocodilia]]'''
|1={{clade
   |label1=[[Alligatoridae]]
   |1={{clade
      |label1=[[Caimaninae]]
        |1={{clade
           |1={{clade
              |1=''[[Caiman (genus)|Caiman]]'' [[File:Caiman crocodilus llanos white background.JPG|90 px]]
              |2=''[[Melanosuchus]]'' [[File:Melanosuchus niger white background.jpg|120 px]] }}
           |2=''[[Paleosuchus]]'' [[File:Dwarf Caiman white background.jpg|90 px]] }}
      |label2=[[Alligatorinae]]
        |2=''[[Alligator]]'' [[File:Alligator white background.jpg|100 px]] }}
   |label2=[[Longirostres]]
   |2={{clade
   |label1='''Crocodylidae'''
   |1={{clade
      |1=''[[Crocodylus]]'' [[File:Siamese Crocodile white background.jpg|90 px]]
      |2={{clade
         |1=''[[Mecistops]]'' [[File:Crocodylus cataphractus faux-gavial d'Afrique2 white background.JPG|90 px]]
         |2=''[[Osteolaemus]]'' [[File:Bristol.zoo.westafrican.dwarf.croc.arp. white background.jpg|90 px]] }} }}
   |label2=[[Gavialidae]]
   |2={{clade
      |1=''[[Gavialis]]'' [[File:Gavialis gangeticus (Gharial, Gavial) white background.jpg|110 px]]
      |2=''[[Tomistoma]]'' [[File:Tomistoma schlegelii. white background.JPG|90 px]]
}} }} }} }}

Below is a more detailed cladogram of Crocodylidae, based on a 2021 study using [[paleogenomics]] that extracted DNA from the extinct ''[[Voay]]''.<ref name="Hekkala2021"/>
{{clade| style=font-size:85%;line-height:85%
|label1='''Crocodylidae'''
|sublabel1=([[crown group]])
|1={{clade
 |label1=[[Osteolaeminae]]
 |1={{clade
  |1={{clade
   |1=''Mecistops cataphractus'' [[West African slender-snouted crocodile]]
   |2=''[[Euthecodon]]''{{extinct}} }}
  |2={{clade
   |1=''[[Brochuchus]]''{{extinct}}
   |2={{clade
    |1=''[[Rimasuchus]]''{{extinct}}
    |2={{clade
     |1=''Osteolaemus osborni'' [[Osborn's dwarf crocodile]]
     |2=''Osteolaemus tetraspis'' [[Dwarf crocodile]] }} }} }} }}
 |label2=[[Crocodylinae]]
 |2={{clade
  |1=''[[Voay]]''{{extinct}}
  |label2=''[[Crocodylus]]''
  |2={{clade
   |1={{clade
    |1={{clade
     |1=''[[Crocodylus anthropophagus]]''{{extinct}}
     |2=''[[Crocodylus thorbjarnarsoni]]''{{extinct}} }}
    |2={{clade
     |1=''[[Crocodylus palaeindicus]]''{{extinct}}
     |2=''Crocodylus'' Tirari Desert{{extinct}} }} }}
   |2={{clade
    |1={{clade
     |1={{clade
      |1=''Crocodylus johnstoni'' [[Freshwater crocodile]]
      |2={{clade
       |1=''Crocodylus novaeguineae'' [[New Guinea crocodile]]
       |2=''Crocodylus mindorensis'' [[Philippine crocodile]] }} }}
     |2={{clade
      |1=''Crocodylus porosus'' [[Saltwater crocodile]]
      |2={{clade
       |1=''Crocodylus siamensis'' [[Siamese crocodile]]
       |2=''Crocodylus palustris'' [[Mugger crocodile]] }} }} }}
    |2={{clade
     |1={{clade
      |1=''[[Crocodylus checchiai]]''{{extinct}}
      |2=''[[Crocodylus falconensis]]''{{extinct}} }}
     |2={{clade
      |1=''Crocodylus suchus'' [[West African crocodile]]
      |2={{clade
       |1=''Crocodylus niloticus'' [[Nile crocodile]]
       |2={{clade
        |1={{clade
         |1=''Crocodylus moreletii'' [[Morelet's crocodile]]
         |2=''Crocodylus rhombifer'' [[Cuban crocodile]] }}
        |2={{clade
         |1=''Crocodylus intermedius'' [[Orinoco crocodile]]
         |2=''Crocodylus acutus'' [[American crocodile]] }} }} }} }} }} }} }} }} }} }}

Alternatively, some [[morphology (biology)|morphological]] studies have recovered ''[[Mecistops]]'' as a [[basal (phylogeny)|basal]] member of [[Crocodylinae]], more closely related to ''[[Crocodylus]]'' than to ''[[Osteolaemus]]'' and the other members of [[Osteolaeminae]],<ref name="Rio2021"/><ref name="Azzara2021">{{cite journal |last1=Azarra |first1=Beatrice |last2=Boschian |first2=Giovanni |last3=Brochu |first3=Christopher |last4=Delfino |first4=Massimo |last5=Iurino |first5=Dawid Adam |last6=Kimambo |first6=Jackson Stanley |last7=Manzi |first7=Giorgio |last8=Masao |first8=Fidelis T. |last9=Menconero |first9=Sofia |last10=Njau |first10=Jackson K |last11=Cherin |first11=Marco |year=2021 |title=A new cranium of Crocodylus anthropophagus from Olduvai Gorge, northern Tanzania |journal=Rivista Italiana di Paleontologia e Stratigrafia (Research in Paleontology and Stratigraphy) |volume=127 |issue=2 |pages=275–295 |url=https://www.researchgate.net/publication/352560805 |doi=10.13130/2039-4942/15771 |s2cid=237962496 }}</ref> as shown in the cladogram below.<ref name="Azzara2021"/>
{{clade| style=font-size:85%;line-height:85%
|grouplabel1={{clade labels |width=10em; |label1='''Paleoafrican ''Crocodylus''''' |top1=40% |color1=red |label2='''Neotropical ''Crocodylus''''' |top2=60% |color2=black |style2=background-color:#ffffee; |label3='''Indo-Pacific ''Crocodylus''''' |top3=85% |color3=green}}
 |label1='''Crocodylidae'''
 |1={{clade
  |label1='''[[Osteolaeminae]]'''
  |1={{clade
   |1=''[[Rimasuchus lloydi]]''{{extinct}}
   |2={{clade
    |1=''[[Voay robustus]]''{{extinct}}
    |2={{clade
     |1=''Osteolaemus osborni'' [[Osborn's dwarf crocodile]]
     |2=''Osteolaemus tetraspis'' [[Dwarf crocodile]] }} }}
   |3={{clade
    |1=''[["Crocodylus" gariepensis]]''{{extinct}}
    |2={{clade
     |1={{clade
      |1=''[[Brochuchus parvidens]]''{{extinct}}
      |2=''[[Brochuchus pigotti]]''{{extinct}} }}
     |2={{clade
      |1=''[[Euthecodon arambourgi]]''{{extinct}}
      |2=''[[Euthecodon brumpti]]''{{extinct}} }} }} }} }}
  |label2='''[[Crocodylinae]]'''
  |2={{clade
   |1='''''Mecistops''' cataphractus'' [[West African slender-snouted crocodile]]
   |2={{clade
    |style1=background-color:#ffdddd;
    |1={{clade
     |1=''[[Crocodylus thorbjarnarsoni]]''{{extinct}} |barbegin1=red
     |2=''[[Crocodylus anthropophagus]]''{{extinct}} |barend2=red }}
    |2={{clade
     |1=''Crocodylus niloticus'' [[Nile crocodile]]
     |2={{clade
      |1=''[[Crocodylus checchiai]]''{{extinct}}
      |style2=background-color:#ffffee;
      |2=''Crocodylus moreletii'' [[Morelet's crocodile]] |barbegin2=yellow
      |style3=background-color:#ffffee;
      |3=''Crocodylus intermedius'' [[Orinoco crocodile]] |bar3=yellow
      |style4=background-color:#ffffee;
      |4=''Crocodylus acutus'' [[American crocodile]] |bar4=yellow
      |style5=background-color:#ffffee;
      |5=''Crocodylus rhombifer'' [[Cuban crocodile]] |barend5=yellow }}
     |style3=background-color:#ddffdd;
     |3=''[[Crocodylus palaeindicus]]''{{extinct}} |barbegin3=lightgreen |barend3=lightgreen
     |style4=background-color:#ccffcc;
     |4={{clade
      |1=''Crocodylus palustris'' [[Mugger crocodile]] |barbegin1=green
      |2={{clade
       |1={{clade
        |1=''[[Crocodylus ossifragus]]''{{extinct}} |bar1=green
        |2=''Crocodylus siamensis'' [[Siamese crocodile]] |bar2=green }}
       |2={{clade
        |1=''Crocodylus mindorensis'' [[Philippine crocodile]] |bar1=green
        |2=''Crocodylus johnstoni'' [[Freshwater crocodile]] |bar2=green
        |3=''Crocodylus porosus'' [[Saltwater crocodile]] |bar3=green
        |4={{clade
         |1=''Crocodylus raninus'' [[Borneo crocodile]] |bar1=green
         |2=''Crocodylus novaeguineae'' [[New Guinea crocodile]] &nbsp;|barend2=green }} }} }} }} }} }} }} }} }}