User:Armin Reindl/sandbox3

Armin Reindl/sandbox3 Temporal range: Pliocene
Life restoration
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Order:	Crocodilia
Family:	Gavialidae
Subfamily:	Gavialinae
Genus:	†Rhamphosuchus Falconer & Cautley, 1840
Type species
†Rhamphosuchus crassidens Falconer & Cautley, 1840
Other species
†R. pachyrhynchus Lydekker, 1886
Synonyms
†Gavialis breviceps? Pilgrim, 1912 †Gavialis curvirostris var. gajensis? Pilgrim, 1912

Rhamphosuchus ("Beak crocodile") is an extinct genus of gavialid crocodylians. It lived during the Pliocene and its fossils have been found in two regions; the Siwalik Hills of Pakistan and India as well as the Sindh region of Pakistan. The genus contains two species, R. crassidens and R. pachyrhynchus, with the latter originally assigned to the genus Gavialis.

History and naming

Some species originally assigned to the genus Gavialis has been reassigned to this genus. Gavialis was reevaluated in 2018 based on specimens in the Natural History Museum, London 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.

Description

Size

Historically, many palaeontologists estimated that it was one of the largest, if not the largest crocodylian that ever lived, reaching an estimated length of 15 to 18 m (49 to 59 ft). 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 of Peru and Brazil, 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 alligatoroid Deinosuchus, the Early Cretaceous pholidosaurid Sarcosuchus and the Miocene gavialid Gryposuchus, at 10.6 m, 9.5 m and 10 m, respectively.

Phylogeny

Rhamphosuchus was previously regarded as a close relative of the modern false gharial within the subfamily Tomistominae. However, Tomistominae in its traditional sense is now known to be paraphyletic, and a 2022 study by Iijima and colleagues recovered Rhamphosuchus as a derived member of the subfamily Gavialinae instead.

Paleobiology

Rhamphosuchus probably had a more generalized predatory diet than the piscivory of other "tomistomines".