Gavialidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of large

semiaquatic In biology, being semi-aquatic refers to various macroorganisms that live regularly in both aquatic and terrestrial environments. When referring to animals, the term describes those that actively spend part of their daily time in water (in ...

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 with elongated, narrow snouts. Gavialidae consists of two

living Living or The Living may refer to: Common meanings *Life, a condition that distinguishes organisms from inorganic objects and dead organisms ** Living species, one that is not extinct *Personal life, the course of an individual human's life * ...

species, 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 ...

(''Gavialis gangeticus'') and the

false gharial The false gharial (''Tomistoma schlegelii''), also known by the names Malayan gharial, Sunda gharial and tomistoma is a freshwater crocodilian of the Family (biology), family Gavialidae native to Peninsular Malaysia, Borneo, Sumatra and Java. It ...

(''Tomistoma schlegelii''), both occurring in Asia. Many

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

members are known from a broader range, including the recently extinct '' Hanyusuchus''. Gavialids are generally regarded as lacking the jaw strength to capture the large mammalian prey favoured by crocodiles and

alligator An alligator, or colloquially gator, is a large reptile in the genus ''Alligator'' of the Family (biology), family Alligatoridae in the Order (biology), order Crocodilia. The two Extant taxon, extant species are the American alligator (''A. mis ...

s of similar size so their thin snout is best used to catch fish, however the false gharial has been found to have a generalist diet with mature adults preying upon larger vertebrates, such as

ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...

Taxonomy

The family Gavialidae was proposed by Arthur Adams in 1854 for reptiles with a very long and slender muzzle, webbed feet and nearly equal teeth. It is currently recognized as 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 ...

, meaning that it only includes 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 all

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

(living) gavialids (the

and

) and their descendants (living or

). Traditionally, crocodiles and alligators were considered more closely related and grouped together in the clade Brevirostres, to the exclusion of the gharials. 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. The new clade

Longirostres Longirostres is a clade of crocodilians that includes the crocodiles and the gavialids, to the exclusion of the alligatoroids. Defined in 2003 by Harshman ''et al.'', Longirostres is a crown group defined phylogenetically as including the last ...

was named by Harshman ''et al.'' in 2003. In addition, these recent molecular DNA studies consistently indicate that the

(''Tomistoma'') (and by inference other related extinct forms) traditionally viewed as belonging to the crocodylian subfamily Tomistominae actually belong to

Gavialoidea Gavialoidea is one of three superfamily (zoology), superfamilies of crocodylians, the other two being Alligatoroidea and Crocodyloidea. Although many extinct species are known, only the gharial ''Gavialis gangeticus'' and the false gharial ''Tomi ...

(and Gavialidae). As its name suggests, 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 ...

as close relatives of

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, based solely on morphological evidence. A 2018

tip dating Tip dating is a technique used in molecular dating that allows the inference of time-calibrated phylogenetic trees. Its defining feature is that it uses the ages of the samples to provide time information for the analysis, in contrast with traditio ...

study by Lee & Yates simultaneously using morphological, molecular (

), and

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

(

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

age) data established the inter-relationships within

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 ...

, which was expanded upon in 2021 by Hekkala ''et al.'' using paleogenomics by extracting DNA from the extinct ''

Voay ''Voay'' is an extinct genus of crocodile from Madagascar that lived during the Late Pleistocene to Holocene, containing only one species, ''V. robustus''. Numerous subfossils have been found, including complete skulls, noted for their distinctiv ...

''. The tip dating analysis resolved the extinct ''

Thoracosaurus ''Thoracosaurus'' (chest lizard) is an extinct genus of long-snouted eusuchian which existed during the Late Cretaceous and Early Paleocene in North America and Europe. Taxonomy ''Thoracosaurus'' had traditionally been thought to be related to ...

'' and similar extinct close relatives ("thoracosaurs") as outside of Gavialoidea due to the large time difference. They concluded that the only possible explanation for the morphological data placing thoracosaurs within the gharial lineage was a significant amount of homoplastic

convergence Convergence may refer to: Arts and media Literature *''Convergence'' (book series), edited by Ruth Nanda Anshen *Convergence (comics), "Convergence" (comics), two separate story lines published by DC Comics: **A four-part crossover storyline that ...

between thoracosaurs and ''Gavialis''. The below

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

from latest study shows Gavialidae's placement within

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 ...

: Here is a more detailed cladogram that shows the proposed

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

of Gavialidae including

members:

Species list

Family Gavialidae *Subfamily Tomistominae **Genus '' Gavialosuchus''? **Genus '' Maomingosuchus''? **Genus '' Melitosaurus'' **Genus ''

Paratomistoma ''Paratomistoma'' (meaning "next to or near ''Tomistoma''") is an extinct monospecific genus of gavialoid crocodylian. It is based on the holotype specimen CGM 42188, a partial posterior skull and lower jaw discovered at Wadi Hitan, Egyp ...

''? **Genus '' Thecachampsa''? **Genus ''

Tomistoma ''Tomistoma'' is a genus of gavialid crocodilians. They are noted for their long narrow snouts used to catch fish, similar to the gharial. ''Tomistoma'' contains one extant (living) member, the false gharial (''Tomistoma schlegelii''), as well ...

'' ***''Tomistoma schlegelii'',

or Malayan gharial ***'' Tomistoma lusitanicum'' *Subfamily

Gavialinae Gavialinae is a subfamily of large semiaquatic crocodilian reptiles, resembling crocodiles, but with much thinner snouts. Gavialinae is one of the two major subfamilies within the family Gavialidae - the other being the subfamily Tomistominae, w ...

**Genus ''

Aktiogavialis ''Aktiogavialis'' is an extinct genus of crocodylian that lived from the Oligocene until the Miocene in what is now the Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the A ...

'' **Genus ''

Argochampsa ''Argochampsa'' (meaning "Argo crocodile", in reference to the mythological ''Argo'' of Jason) is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodilian, related to modern gharials. It lived in the Paleocene o ...

''? **Genus '' Dadagavialis'' **Genus ''

Eogavialis ''Eogavialis'' is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodylian. It superficially resembles ''Tomistoma schlegelii'', the extant false gharial, and consequently material from the genus was originally ...

''? **Genus ''

Eosuchus ''Eosuchus'' ("dawn crocodile") is an extinct genus of eusuchian crocodylomorph, traditionally regarded as a gavialoid crocodilian. It might have been among the most basal of all gavialoids, lying crownward of all other known members of the ...

''? **Genus ''

Eothoracosaurus ''Eothoracosaurus'' is an extinct monospecific genus of eusuchian crocodylomorphs found in Eastern United States which existed during the Late Cretaceous period. ''Eothoracosaurus'' is considered to belong to an informally named clade called the ...

''? **Genus ''

Gavialis ''Gavialis'' is a genus of crocodylians that includes the living gharial ''Gavialis gangeticus'' and one known extinct species, '' Gavialis bengawanicus.'' ''G. gangeticus'' comes from the Indian Subcontinent, while ''G. bengawanicus'' is know ...

'' ***''Gavialis gangeticus'',

***'' Gavialis bengawanicus'' **Genus '' Gavialosuchus''? **Genus ''

Gryposuchus ''Gryposuchus'' is an extinct genus of gavialid crocodilian. Fossils have been found from Argentina, Colombia, Venezuela, Brazil and the Peruvian Amazon. The genus existed during the Miocene epoch (Colhuehuapian to Huayquerian). One recently d ...

''? (may by

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

, along with

Gryposuchinae Gryposuchinae is an extinct subfamily of gavialid crocodylians. Gryposuchines lived mainly in the Miocene of South America. However, '' "Ikanogavialis" papuensis'' may have survived more recently, into the Late Pleistocene/Holocene. Most were lo ...

) **Genus '' Hanyusuchus'' **Genus '' Harpacochampsa''? **Genus '' Hesperogavialis'' **Genus '' Ikanogavialis'' **Genus '' Maomingosuchus''? **Genus ''

Ocepesuchus ''Ocepesuchus'' (meaning "Ocepe crocodile", in reference to the OCP, or Office Chérifien des Phosphates, a phosphate-mining company that participated in the excavation of the specimen) is an extinct genus of gavialoid crocodilian, related to m ...

'' **Genus ''

''? **Genus ''

Penghusuchus ''Penghusuchus'' is an extinct genus of gavialid crocodylian. It is known from a skeleton found in Middle to Upper Miocene rocks of Penghu Island, off Taiwan. The taxon was described in 2009 by Shan and colleagues; the type species is ''P. pani ...

'' **Genus ''

Piscogavialis ''Piscogavialis'' is an extinct monospecific genus of Gryposuchinae, gryposuchine Gavialidae, gavialid crocodylian. The only species yet known is ''P. jugaliperforatus''. Fossils of ''Piscogavialis'' have been found from the Miocene, Mio-Pliocene ...

'' **Genus '' Rhamphosuchus'' **Genus '' Siquisiquesuchus'' **Genus ''

''? **Genus ''

Toyotamaphimeia ''Toyotamaphimeia'' (named after Toyotama-hime) is a genus of extinct gavialid crocodylian which lived in Japan and Taiwan during the Middle Pleistocene. A specimen recovered in 1964 at Osaka University during the construction of a new science bu ...

'' † Indicates extinct group

Extant species

References

{{Authority control Crocodilian families Taxa named by Andrew Leith Adams Extant Eocene first appearances