Protosuchia

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Protosuchia
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
Clade: Crocodyliformes
Informal group: Protosuchia
Mook, 1934
Subgroups

See text.

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 be 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.