From Wikipedia, the free encyclopedia
  (Redirected from Crocodyliform)
Jump to: navigation, search
Temporal range: Late Triassic–Recent, 225–0 Ma
Protosuchus BW.jpg
Protosuchus, an early crocodyliform
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Crocodylomorpha
Clade: Crocodyliformes
Hay, 1930

Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the only members of Crocodylomorpha who survived beyond the Early Jurassic, while the crocodylomorphs was the only Pseudosuchia group who survived the Triassic–Jurassic extinction event.

In 1988, Michael J. Benton and James M. Clark argued that all traditional names for well-known groups of animals should be restricted to their crown clades, that is, used only for natural groups comprising all living members of any given lineage. This posed a problem for the crocodilians, because the name Crocodylia, while used in various ways by various scientists, had always included not only living crocodilians but many of their extinct ancestors known only from the fossil record.[1]

Benton and Clark's solution to this issue was to restrict the name Crocodylia to the group containing modern alligators, crocodiles, and gharials, plus any extinct members of those specific families. The traditional group "Crocodylia" was replaced with the name Crocodyliformes, which included many of the extinct families that the new definition left out. Clark and Benton did not initially provide an exact definition for Crocodyliformes; but, in 2001, Paul Sereno and colleagues defined it as the clade including Protosuchus richardsoni and the Nile crocodile, plus all descendants of their common ancestor.[2]

Chris Brochu agreed with the assessment that Crocodylia as a name has never had stable contents, and that a series of clades larger than the crown group Crocodylia (including Crocodyliformes and the slightly more inclusive clade Crocodylomorpha) was a good solution.[3] However, in a 2008 paper, Jeremy Martin and Benton, the authors reversed the previous opinion (co-authored by Benton) that Crocodylia should be restricted to the crown group, suggesting that Crocodyliformes should be considered a synonym of a more inclusive Crocodylia, and thus replaced.[4] Brochu and colleagues rejected this proposal, arguing that the crown definition of Crocodylia is the standard meaning both within and beyond the crocodyliform systematics community.[5]


Below is a simplified cladogram based on Fiorelli and Calvo (2007).[6]












 "Kayenta Form"



In 2012, paleontologists Mario Bronzati, Felipe Chinaglia Montefeltro, and Max C. Langer conducted a broad phylogenetic analysis to produce supertrees of Crocodyliformes, including 184 species. The most parsimonious trees were highly resolved, meaning the phylogenetic relationships found in the analysis were highly likely. Below is a consensus tree from the study:[7]

Kayentasuchus walkeri


Orthosuchus stormbergi

Protosuchus richardsoni

Hemiprotosuchus leali

Kayenta Form

Edentosuchus tienshanensis

Zaraasuchus shepardi

Las Hoyas Croc

Gobiosuchus kielanae

Eopneumatosuchus colberti

Zosuchus davidsoni

Sichuanosuchus shuhanensis

Sichuanosuchus huidongensis

Shantungosuchus hangjinensis

Shantungosuchus chuhsiensis

Shantungosuchus brachycephalus

Neuquensuchus universitas

Shartegosuchus asperopalatum

Fruita Form (Fruitachampsa callisoni)

Hsisosuchus dashanpuensis

Hsisosuchus chungkingensis


Araripesuchus wegeneri

Araripesuchus tsangatsangana

Araripesuchus buitreraensis

Araripesuchus patagonicus

Araripesuchus gomesii

Uruguaysuchus terrai

Uruguaysuchus aznarezi

Libycosuchus brevirostris

Simosuchus clarki

Malawisuchus mwakasyungutiensis

Candidodon itapecuruense

Notosuchus terrestris

Comahuesuchus brachybuccalis

Mariliasuchus amarali

Yacarerani boliviensis

Pakasuchus kapilimai

Adamantinasuchus navae

Stratiotosuchus maxhechti

Pehuenchesuchus enderi

Pabwehshi pakistanensis

Iberosuchus macrodon

Eremosuchus elkoholicus


Bergisuchus dietrichbergi

Baurusuchus salgadoensis

Baurusuchus pachechoi

Chimaerasuchus paradoxus

Sphagesaurus huenei

Sphagesaurus montealtensis

Sebecus huilensis

Sebecus icaeorhinus

Itaborai Croc

Bretesuchus bonapartei

Anatosuchus minor

Barcinosuchus gradilis

Itasuchus jesuinoi

Miadanasuchus oblita

Trematochampsa taqueti

Caririsuchus camposi

Kaprosuchus saharicus

Mahajangasuchus insignis


Hamadasuchus rebouli

Montealtosuchus arrudacamposi

Uberabasuchus terrificus

Peirosaurus torminni

Lomasuchus palpebrosus



  1. ^ Benton, M.J. and Clark, J.M. (1988). "Archosaur phylogeny and the relationships of the Crocodylia." Pp. 295–338 in Benton, M.J. (ed.), The phylogeny and classification of the Tetrapods, volume 1. Oxford: Clarendon Press.
  2. ^ Sereno, P.C., Larson, H.C.E., Sidor, C.A. and Gado, B. (2001). "The giant crocodyliform Sarcosuchus from the Cretaceous of Africa." Science, 294: 1516–1519.
  3. ^ Brochu, C.A. (2003). "Phylogenetic approaches toward crocodylian history." Annu. Rev. Earth Planet. Sci., 31: 357–397.
  4. ^ Martin, J.E. and Benton, M.J. (2008). "Crown Clades in Vertebrate Nomenclature: Correcting the Definition of Crocodylia." Systematic Biology, 57: 1,173 — 181.
  5. ^ Brochu, A.C., Wagner, J.R., Jouve, S., Sumrall, C.D. and Densmore, L.D. (2009). "A correction corrected: consensus over the meaning of Crocodylia and why it matters" Systematic Biology, 58: 537-543.
  6. ^ Fiorelli LE, Calvo JO. 2007. The first "protosuchian" (Archosauria: Crocodyliformes) from the Cretaceous (Santonian) of Gondwana. Arquivos do Museu Nacional, Rio de Janeiro 65 (4): 417-459.
  7. ^ Bronzati, M.; Montefeltro, F. C.; Langer, M. C. (2012). "A species-level supertree of Crocodyliformes". Historical Biology: 1. doi:10.1080/08912963.2012.662680.