''Rhamphosuchus'' ("Beak crocodile") is an

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 ...

genus of gavialid crocodylians. It lived during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Siwalik Hills of

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

and

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

as well as the

Sindh Sindh ( ; ; , ; abbr. SD, historically romanized as Sind (caliphal province), Sind or Scinde) is a Administrative units of Pakistan, province of Pakistan. Located in the Geography of Pakistan, southeastern region of the country, Sindh is t ...

region of

. The genus contains two species, ''R. crassidens'' and ''R. pachyrhynchus'', with the latter originally assigned to 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 ...

''.

Overview

Historically, many palaeontologists estimated that it was one of the largest, if not the largest crocodylian that ever lived, reaching an estimated length of . However, a more recent study suggests that the animal may have been 8–11 m (26 to 36 ft) in length, and therefore is not the largest known crocodylian. Another crocodylian, '' Purussaurus'', from the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

and

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, is known from an equally incomplete fossil set. It is estimated to have been similar in length to the initial estimates at approximately 9.2–10.3 m (about 30–34 ft). However, this would mean that it would have been somewhat larger in size if the more recent size estimates for ''Rhamphosuchus'' are correct. If the most recent estimate is correct, then several other extinct crcoodilians and crocodylomorphs likely surpassed ''Rhamphosuchus'' in weight, such as the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

alligatoroid ''

Deinosuchus ''Deinosuchus'' is an extinct genus of eusuchian, either an Alligatoroidea, alligatoroid Crocodilia, crocodilian or a stem-group crocodilian, which lived during the Late Cretaceous around . The first remains were discovered in North Carolina ...

'', the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

pholidosaurid Pholidosauridae is an extinct Family (biology), 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 Tu ...

'' Sarcosuchus'' and the

gavialid '' Gryposuchus'', at 10.6 m, 9.5 m and 10 m, respectively. ''Rhamphosuchus'' was previously regarded as a close relative of the modern

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 ...

within the subfamily Tomistominae. However, Tomistominae in its traditional sense is now known to be

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 ...

, and a 2022 study by Iijima and colleagues recovered ''Rhamphosuchus'' as a derived member of the subfamily Gavialinae instead. ''Rhamphosuchus'' probably had a more generalized predatory diet than the piscivory of other "tomistomines". Some species originally assigned to the genus ''

'' has been reassigned to this genus. ''Gavialis'' was reevaluated in 2018 based on specimens in the

Natural History Museum, London The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum (Lo ...

that were collected in the Sivalik Hills. The author concluded that ''G. gangeticus'' and '' G. bengawanicus'' are the only two species in the genus ''Gavialis'', and proposed ''Rhamphosuchus'' to include ''G. leptodus'', ''G. pachyrhynchus'', '' G. curvirostris'' and ''G. breviceps''. The 2025 study assigned ''G. pachyrhynchus'' and its junior synonym ''G. breviceps'' under the genus ''Rhamphosuchus'' as ''R. pachyrhynchus'', and recovered this genus either as a member of Gavialoidea outside Gavialidae or as a member of Tomistominae. The same study also assigned ''G. curvirostris'' to its own genus, '' Pseudogavialis''.

References

{{Taxonbar, from=Q899095 Gavialidae Pliocene crocodylomorphs Pliocene reptiles of Asia Prehistoric pseudosuchian genera Fossil taxa described in 1840

Overview

See also

References