Gavialis browni

Summary

Gavialis browni is an extinct species of the crocodylian genus Gavialis and a close relative of the living gharial Gavialis gangeticus.

Gavialis browni
Temporal range: Late Miocene, 11.6–5.3 Ma[1]
Skull of Gavialis browni (AMNH 6279) in the American Museum of Natural History
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Gavialidae
Genus: Gavialis
Species:
G. browni
Binomial name
Gavialis browni

G. browni lived about 5 million years ago in the Sivalik Hills of Pakistan. G. browni can be distinguished from G. gangeticus by its more closely spaced eyes and a narrower frontal bone.[2] The species was named in 1932 by paleontologist Charles Mook. Mook described it as a transitional form between the most primitive Gavialis species, Gavialis dixoni, and the most advanced, the modern gharial (although G. dixoni is now placed outside Gavialis in its own genus, Dollosuchus, and may be more closely related to crocodiles than to the gharial).[3] G. browni has a longer snout with more teeth than Dollosuchus, but it is not as long and does not have as many teeth as that of the gharial.[4] G. browni has also been proposed to be moved to a genus other than Gavialis.[5]

Below is a cladogram that shows the proposed phylogeny within Gavialidae, including extinct members:[6]

Gavialidae

References edit

  1. ^ Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
  2. ^ Claude, J.; Naksri, W.; Boonchai, N.; Buffetaut, E.; Duangkrayom, J.; Laojumpon, C.; Jintasakul, P.; Lauprasert, K.; Martin, J.; Suteethorn, V.; Tong, H. (2011). "Neogene reptiles of northeastern Thailand and their paleogeographical significance". Annales de Paléontologie. 97 (3–4): 113. doi:10.1016/j.annpal.2011.08.002.
  3. ^ Brochu, C. A. (2007). "Systematics and Taxonomy of Eocene Tomistomine Crocodylians from Britain and Northern Europe". Palaeontology. 50 (4): 917–928. doi:10.1111/j.1475-4983.2007.00679.x.
  4. ^ Mook, C. C. (1932). "A new species of fossil gavial from the Siwalik Beds" (PDF). American Museum Novitates (514): 1–5.
  5. ^ Martin, J. E.; Buffetaut, E.; Naksri, W.; Lauprasert, K.; Claude, J. (2012). Butler, Richard J (ed.). "Gavialis from the Pleistocene of Thailand and Its Relevance for Drainage Connections from India to Java". PLOS ONE. 7 (9): e44541. Bibcode:2012PLoSO...744541M. doi:10.1371/journal.pone.0044541. PMC 3445548. PMID 23028557.
  6. ^ 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. PMC 6030529. PMID 30051855.