Longirostres is a

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 ...

crocodilia Crocodilia () is an 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 crocodylomorph pseudosuchia ...

ns that includes the

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large, semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term "crocodile" is sometimes used more loosely to include ...

s and the gavialids, to the exclusion of the alligatoroids. Defined in 2003 by Harshman ''et al.'', Longirostres is a

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor ...

defined

phylogenetic 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 dat ...

ally as including the

last common ancestor A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assu ...

of ''

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 '' Gavialis gangeticus'' and all of its descendants. Traditionally, crocodiles and alligators were considered more closely related and grouped together in the clade Brevirostres, to the exclusion of the

gharial The gharial (''Gavialis gangeticus''), also known as gavial or fish-eating crocodile, is a crocodilian in the family (biology), family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males ...

s. This classification was based on morphological studies primarily focused on analyzing skeletal traits of living and extinct fossil species. However, recent molecular studies using

DNA sequencing DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, thymine, cytosine, and guanine. The ...

have rejected Brevirostres upon finding the crocodiles and gavialids to be more closely related than the alligators. Below is a cladogram showing the relationships of the major crocodilian groups based on molecular studies:

References

{{Taxonbar, from=Q107389342 Crocodilia