Metasuchia is a major

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

within the

superorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

Crocodylomorpha Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. Extinct crocodylomorphs were considerably mor ...

. It is split into two main groups,

Notosuchia Notosuchia is a clade of primarily Gondwanan mesoeucrocodylian Crocodylomorpha, crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogeny, phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group ...

and

Neosuchia Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all Crocodylomorpha, crocodylomorphs more closely related to ''Croc ...

. Notosuchia is an extinct group that contains primarily small-bodied

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

taxa with

heterodont In anatomy, a heterodont (from Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology. Human dentition is heterodont and diphyodont as an example. In vertebrates, heterodont pertains to animals wher ...

dentition. Neosuchia includes the extant

crocodylia Crocodilia () is an Order (biology), order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorp ...

ns and basal taxa, such as peirosaurids and pholidosaurids. It is

phylogenetically In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

defined by Sereno ''et al.'' (2001) as a clade containing '' Notosuchus terrestris'', ''

Crocodylus niloticus The Nile crocodile (''Crocodylus niloticus'') is a large crocodilian native to freshwater habitats in Africa, where it is present in 26 countries. It is widely distributed in sub-Saharan Africa, occurring mostly in the eastern, southern, and ce ...

'', and all descendants of their common ancestor.

Phylogenetics

The phylogeny of basal metasuchians has experienced many revisions in recent years. The phylogeny of notosuchians has been particularly revised, with the construction of Sebecia by Larsson and Sues (2007) to include peirosaurids in the clade. Previously, peirosaurids were placed outside Notosuchia. Larsson and Sues (2007) also suggested that Sebecosuchia (containing the families Baurusuchidae and Sebecidae) was

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

, as '' Baurusuchus'' was placed outside Sebecia, which itself was placed outside Notosuchia. However, more recent phylogenetic studies have placed '' Baurusuchus'' within Notosuchia once again, although it is still not considered to be a sebecosuchian. In 2012, a phylogenetic study was done 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. As such, below is the consensus tree from the study, focusing on the Metasuchian branch of the tree.

References

External links

Metasuchia
in the

Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...

{{Taxonbar, from=Q3307307 Crocodyliformes Jurassic crocodylomorphs Cretaceous crocodylomorphs Paleogene crocodylomorphs Neogene crocodylomorphs Extant Early Jurassic first appearances