Protosuchia

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Protosuchians
Temporal range: Late Triassic - Late Cretaceous
Protosuchus richardsoni AMNH 3024 cast.jpg
A skeleton of Protosuchus richardsoni in the American Museum of Natural History
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Crocodylomorpha
Clade: Crocodyliformes
Informal group: Protosuchia
Mook, 1934

Protosuchia is a group of extinct Mesozoic crocodyliforms. They were small in size (~1 meter in length) and terrestrial. In phylogenetic terms, Protosuchia is considered an informal group because it is a grade of basal crocodyliforms, not a true clade.

Classification[edit]

Recent phylogenetic analyses have not supported Protosuchia as a natural group. However, two studies found a clade of Late Triassic-Early Jurassic animals:[1][2]

Both of these studies also found a clade more closely related to Hsisosuchus and Mesoeucrocodylia consisting of Late Jurassic-Late Cretaceous genera:[1][2]

However, other possible protosuchians from the Late Cretaceous of China-Mongolia, the Gobiosuchidae (Gobiosuchus and Zaraasuchus), have been found to either intermediate between these two clades,[1] or members of the Sichuanosuchus clade.[2] There is also another family of Late Jurassic-Late Cretaceous genera, the Shartegosuchidae (e.g. Kyasuchus, Shartegosuchus and Nominosuchus).

Below is a cladogram from Fiorelli and Calvo (2007).[2] Protosuchians are marked by the green bracket.

Crocodylomorpha 


 Terrestrisuchus



 Dibothrosuchus



 Crocodyliformes 

 Gobiosuchidae 

 Gobiosuchus 



 Zaraasuchus 





 Orthosuchus 



 Protosuchidae 

 Protosuchus 



 Hemiprotosuchus 





 "Kayenta Form" 



 Edentosuchus 






 Mesoeucrocodylia 


 "Fruitachampsa"




 Zosuchus




 Sichuanosuchus




 Shantungosuchus



 Neuquensuchus





 



 Hsisosuchus


 Metasuchia 

 Neosuchia



 Peirosauridae



 Notosuchia







Protosuchians

References[edit]

  1. ^ a b c Pol D, Ji S-a, Clark JM, Chiappe LM. 2004. Basal crocodyliforms from the Lower Cretaceous Tugulu Group (Xinjiang, China), and the phylogenetic position of Edentosuchus. Cretaceous Research 25: 603-622.
  2. ^ a b c d 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.