Gavialinae is a subfamily of large

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semi aquatic animals include: * Ve ...

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 livi ...

n reptiles, resembling crocodiles, but with much thinner snouts. Gavialinae is one of the two major subfamilies within the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Gavialidae Gavialidae is a family of large semiaquatic crocodilians with elongated, narrow snouts. Gavialidae consists of two living species, the gharial (''Gavialis gangeticus'') and the false gharial (''Tomistoma schlegelii''), both occurring in Asia. Ma ...

- the other being the subfamily

Tomistominae Tomistominae is a subfamily of crocodylians that includes one living species, the false gharial. Many more extinct species are known, extending the range of the subfamily back to the Eocene epoch. In contrast to the false gharial, which is a fres ...

, which contains the false gharial and extinct relatives.

Classification

Gavialinae was first proposed by Nopcsa in 1923, and was

cladistically Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

defined by Brochu in 2003 as ''Gavialis gangeticus'' (the gharial) and all crocodylians more closely related to it than to ''Tomistoma schlegelii'' (the false gharial). This is a stem-based definition for gavialinae, and means that it includes more basal extinct gavialine ancestors that are more closely related to the gharial than to the false gharial. The false gharial was once thought to be only distantly related to the gharial despite its similar appearance. The false gharial and other tomistomines were traditionally classified within the superfamily

Crocodyloidea Crocodyloidea is one of three superfamilies of crocodilians, the other two being Alligatoroidea and Gavialoidea, and it includes the crocodiles. Crocodyloidea may also include the extinct Mekosuchinae, native to Australasia from the Eocene to th ...

as close relatives of crocodiles, based solely on morphological evidence. However, recent molecular studies using DNA sequencing have found that they are in fact more closely related to each other than any other extant (living) crocodilian. The placement of extinct gavialids between Gavialinae and Tomistominae is unresolved. The below

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 ...

is from the 2022 Iijima ''et al.'' study:

References

{{Taxonbar, from=Q13640440 Gavialidae Animal subfamilies