Biology:Gavialis

From HandWiki

Gavialis is a genus of crocodilians that includes the living gharial Gavialis gangeticus and one known extinct species, Gavialis bengawanicus.[1] G. gangeticus comes from the Indian subcontinent,[2] while G. bengawanicus is known from Java. Gavialis likely first appeared in the Indian Subcontinent in the Pliocene and dispersed into the Malay Archipelago through a path called the Siva–Malayan route in the Quaternary. Remains attributed to Gavialis have also been found on Sulawesi and Woodlark Island east of the Wallace Line, suggesting a prehistoric lineage of Gavialis was able to traverse marine environments and reach places possibly as far as western Oceania.[3]

The 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, with G. hysudricus as a junior synonym of G. gangeticus. Rhamphosuchus is proposed to include G. leptodus, G. pachyrhynchus, G. curvirostris and G. breviceps. The species G. browni and G. lewisi require further revisions.[1] G. dixoni has been assigned its own genus, Dollosuchus.[4] In 2025, G. pachyrhynchus and its junior synonym G. breviceps were included within the genus Rhamphosuchus as a new combination R. pachyrhynchus, while G. curvirostris was assigned to its own genus, Pseudogavialis.[5]

The below cladogram of the major extant crocodile groups is based on the latest molecular studies, and shows the gharial's close relationship to the false gharial, and how the gavialids and crocodiles are more closely related than the alligatoroids:[6][7][8][9][10]

Crocodilia
Alligatoridae
Caimaninae

Caiman 90 px

Melanosuchus 120 px

Paleosuchus 90 px

Alligatorinae

Alligator 100 px

Longirostres
Crocodylidae

Crocodylus 90 px

Mecistops 90 px

Osteolaemus 90 px

Gavialidae

Gavialis 110 px

Tomistoma 90 px

Here is a more detailed cladogram that shows Gavialis's proposed placement within Gavialidae, including extinct members:[9]

Gavialidae

Gavialis gangeticus Gharial

Gavialis bengawanicus

Gavialis browni

Gryposuchus colombianus

Ikanogavialis

Gryposuchus pachakamue

Piscogavialis

Harpacochampsa

Toyotamaphimeia

Penghusuchus

Gavialosuchus

Tomistoma lusitanicum

Tomistoma schlegelii False gharial

References

  1. 1.0 1.1 Martin, J. E. (2018). "The taxonomic content of the genus Gavialis from the Siwalik Hills of India and Pakistan" (in en). Papers in Palaeontology 5 (3): 483–497. doi:10.1002/spp2.1247. https://hal.archives-ouvertes.fr/hal-02123647/file/2019Gavialis.pdf. 
  2. Lull, R. S. (1944). "Fossil gavials from north India". American Journal of Science 242 (8): 417–430. doi:10.2475/ajs.242.8.417. Bibcode1944AmJS..242..417L. 
  3. Delfino, M.; De Vos, J. (2010). "A revision of the Dubois crocodylians, Gavialis bengawanicus and Crocodylus ossifragus, from the Pleistocene Homo erectus beds of Java". Journal of Vertebrate Paleontology 30 (2): 427. doi:10.1080/02724631003617910. Bibcode2010JVPal..30..427D. 
  4. Swinton, W. E. (1937). "The crocodile of Maransart (Dollosuchus dixoni [Owen])". Mémoires du Musée d'Histoire Naturelle de Belgique. 80: 1–44.
  5. Courville, E.; Métais, G.; Antoine, P.-O.; Marivaux, L.; Jouve, S. (2025). "Giant longirostrine crocodylians from the Lower Miocene of Pakistan: new material and taxonomic review". Papers in Palaeontology 11 (3): e70010. doi:10.1002/spp2.70010. 
  6. Harshman, J.; Huddleston, C. J.; Bollback, J. P.; Parsons, T. J.; Braun, M. J. (2003). "True and false gharials: A nuclear gene phylogeny of crocodylia". Systematic Biology 52 (3): 386–402. doi:10.1080/10635150309323. PMID 12775527. http://si-pddr.si.edu/bitstream/handle/10088/6275/2003C_Harshman_et_al.pdf. Retrieved 2021-06-28. 
  7. Gatesy, J.; Amato, G. (2008). "The rapid accumulation of consistent molecular support for intergeneric crocodylian relationships". Molecular Phylogenetics and Evolution 48 (3): 1232–1237. doi:10.1016/j.ympev.2008.02.009. PMID 18372192. 
  8. Erickson, G. M.; Gignac, P. M.; Steppan, S. J.; Lappin, A. K.; Vliet, K. A.; Brueggen, J. A.; Inouye, B. D.; Kledzik, D. et al. (2012). "Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation". PLOS ONE 7 (3). doi:10.1371/journal.pone.0031781. PMID 22431965. Bibcode2012PLoSO...731781E. 
  9. 9.0 9.1 Michael S. Y. Lee; Adam M. Yates (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B 285 (1881). doi:10.1098/rspb.2018.1071. PMID 30051855. 
  10. Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S. et al. (2021-04-27). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus" (in en). Communications Biology 4 (1): 505. doi:10.1038/s42003-021-02017-0. ISSN 2399-3642. PMID 33907305. 

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Wikidata ☰ Q3506745 entry