Gavialis browni explained

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

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.^[1] 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).^[2] 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.^[3] G. browni has also been proposed to be moved to a genus other than Gavialis.^[4]

Below is a cladogram that shows the proposed phylogeny within Gavialidae, including extinct members:^[5]

Notes and References

1. Claude . J. . Naksri . W. . Boonchai . N. . Buffetaut . E. . Duangkrayom . J. . Laojumpon . C. . Jintasakul . P. . Lauprasert . K. . Martin . J. . Suteethorn . 10.1016/j.annpal.2011.08.002 . V. . Tong . H. . Neogene reptiles of northeastern Thailand and their paleogeographical significance . Annales de Paléontologie . 97 . 3–4 . 113 . 2011 .
2. Brochu . C. A. . Systematics and Taxonomy of Eocene Tomistomine Crocodylians from Britain and Northern Europe . 10.1111/j.1475-4983.2007.00679.x . Palaeontology . 50 . 4 . 917–928 . 2007 . free .
3. Mook . C. C. . 1932 . A new species of fossil gavial from the Siwalik Beds. American Museum Novitates . 514 . 1–5 .
4. Martin . J. E. . Buffetaut . E. . Naksri . W. . Lauprasert . K. . Claude . J. . Butler . Richard J . Gavialis from the Pleistocene of Thailand and Its Relevance for Drainage Connections from India to Java . 10.1371/journal.pone.0044541 . PLOS ONE . 7 . 9 . e44541 . 2012 . 23028557. 3445548. 2012PLoSO...744541M . free .
5. 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 . . 285 . 1881 . 10.1098/rspb.2018.1071 . 30051855 . 6030529 . free.