Neosuchia is a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

within

Mesoeucrocodylia Mesoeucrocodylia is the clade that includes Eusuchia and crocodyliforms formerly placed in the paraphyletic group Mesosuchia. The group appeared during the Early Jurassic, and continues to the present day. Diagnosis It was long known that M ...

that includes all modern extant

crocodilia Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living ...

ns and their closest fossil relatives. It is defined as the most inclusive clade containing all

crocodylomorphs 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. During Mesozoic and early Cenozoic times, cr ...

more closely related to ''

Crocodylus niloticus ''Crocodylus'' is a genus of true crocodiles in the family Crocodylidae. Taxonomy The generic name, ''Crocodylus'', was proposed by Josephus Nicolaus Laurenti in 1768. ''Crocodylus'' contains 13–14 extant (living) species and 5 extinct spe ...

'' (the

Nile Crocodile 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 throughout sub-Saharan Africa, occurring mostly in the central, eastern ...

) than to ''

Notosuchus terrestris ''Notosuchus'' (; 'southern crocodile') is an extinct genus of South American notosuchian crocodylomorph. It was terrestrial, living approximately 85 million years ago in the Santonian stage of the Late Cretaceous. Description ''Notosuchus'' wa ...

''. Members of Neosuchia generally share a crocodilian-like bodyform adapted to freshwater aquatic life, as opposed to the terrestrial habits of more basal crocodylomorph groups. The earliest neosuchian is suggested to be the

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...

Calsoyasuchus ''Calsoyasuchus'' (meaning " r. KyrilCalsoyas' crocodile") is a genus of crocodylomorph that lived in the Early Jurassic. Its fossilized remains were found in the Sinemurian-Pliensbachian-age Kayenta Formation on Navajo Nation land in Coconino ...

'', which lived during the

Sinemurian In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is ...

and

Pliensbachian The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago). The Plien ...

stages in North America. It is often identified as a member of

Goniopholididae Goniopholididae is an extinct family of moderate-sized semi-aquatic neosuchian crocodyliformes. Their bodyplan and morphology are convergent on living crocodilians. They lived across Laurasia (Asia, Europe and North America) between the Middle J ...

, though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic.

Characteristics

A tooth notch between the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

and

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

is a basal characteristic of the Neosuchia, although it is lost in some more

derived Derive may refer to: * Derive (computer algebra system), a commercial system made by Texas Instruments * ''Dérive'' (magazine), an Austrian science magazine on urbanism *Dérive, a psychogeographical concept See also * *Derivation (disambiguatio ...

forms, most notably alligatorids.

Classification

* Basal Neosuchia ** Genus ''

Burkesuchus ''Burkesuchus'' (meaning "Coleman Burke's crocodile") is an extinct genus of basal neosuchians from the Upper Jurassic (Tithonian)-aged Toqui Formation of southern Chile. The genus is currently represented by a single species ''B. mallingrandensi ...

''? ** Genus ''

Deltasuchus ''Deltasuchus'' ("delta crocodile") is a genus of neosuchian crocodyliform from the Late Cretaceous of Texas, specifically in the Woodbine Formation, which was a part of the Appalachian continent during the Cretaceous. It is known from one speci ...

'' ** Genus ''

Khoratosuchus ''Khoratosuchus'' is an extinct genus of neosuchian crocodylomorph which existed in northeast Thailand during the early Cretaceous period. Its type species is ''Khoratosuchus jintasakuli''. ''Khoratosuchus'' is the youngest and most advanced Mes ...

'' ** Genus '' Lisboasaurus'' ** Genus ''

Paluxysuchus ''Paluxysuchus'' is an extinct genus of neosuchian crocodyliform known from the Early Cretaceous Twin Mountains Formation (late Aptian stage) of north-central Texas. It contains a single species, ''Paluxysuchus newmani''. ''Paluxysuchus'' is ...

'' ** Genus ''

Stolokrosuchus ''Stolokrosuchus'' is an extinct genus of neosuchian crocodylomorph that lived during the Early Cretaceous. Its fossils, including a skull with a long thin snout and bony knobs on the prefrontal, have been found in Niger. ''Stolokrosuchus'' wa ...

'' ** Genus ''

Wahasuchus ''Wahasuchus'' is a genus of extinct mesoeucrocodylian of the Middle Campanian age found in the Quseir Formation, Egypt. The generic name derives from the Arabic word واحة (''waha''), which means "oasis" and ''souchos'' from the Greek in h ...

''? ** Family Susisuchidae ** Clade Coelognathosuchia *** Family

*** ?Family

Pholidosauridae Pholidosauridae is an extinct family of aquatic neosuchian mesoeucrocodylian crocodylomorphs. Fossils have been found in Europe (Denmark, England, France, Germany, Spain and Sweden), Africa (Algeria, Niger, Mali, Morocco and Tunisia), North Amer ...

** Suborder Tethysuchia *** Family

Elosuchidae ''Elosuchus'' is an extinct genus of neosuchian crocodyliform that lived during the Middle Cretaceous of what is now Africa (Niger, Morocco and Algeria). Description and taxonomy ''Elosuchus'' had an elongated snout like a gharial and was prob ...

*** Family

Dyrosauridae Dyrosauridae is a family of extinct neosuchian crocodyliforms that lived from the Late Cretaceous (Maastrichtian) to the Eocene. Dyrosaurid fossils are globally distributed, having been found in Africa, Asia, Europe, North America and South Ame ...

*** Family

** Family Stomatosuchidae ** Family

Bernissartiidae Bernissartiidae is an extinct family of neosuchian crocodyliformes known from the Early Cretaceous. Bernissartiid fossils have been reported from Belgium, France, Spain, England, Tunisia and the United States. It currently contains two genera, ' ...

** Genus ''

Gilchristosuchus ''Gilchristosuchus'' (meaning "Gilchrist he owners of the ranch where the type specimen was found">type_specimen.html" ;"title="he owners of the ranch where the type specimen">he owners of the ranch where the type specimen was foundcrocodile") i ...

'' ** Suborder

Eusuchia Eusuchia is a clade of crocodylomorphs that first appeared in the Early Cretaceous with '' Hylaeochampsa''. Along with Dyrosauridae and Sebecosuchia, they were the only crocodyliformes who survived the K-T extinction. Since the other two clades ...

Phylogeny

Below is a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

showing the

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationships of neosuchians from Buscalioni ''et al.'', 2011: 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:

References

External links

Neosuchia
in the

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

{{Taxonbar, from=Q3042061 Jurassic crocodylomorphs Cretaceous crocodylomorphs Paleogene crocodylomorphs Neogene crocodylomorphs Extant Early Jurassic first appearances