Tomistoma is agenus ofgavialidcrocodilians. They are noted for their long narrow snouts used to catch fish, similar to thegharial.Tomistoma contains oneextant (living) member, thefalse gharial (Tomistoma schlegelii), as well as potentially several extinct species:T. cairense,T. lusitanicum andT. coppensi. Previously assigned extinct species known from fossils are reclassified as different genera such asEogavialis,Toyotamaphimeia andSutekhsuchus.[2][3][4]
Unlike thegharial, the false gharial's snout broadens considerably towards the base and so is more similar to those of truecrocodiles than the gharial, whoseosteology indicated a distinct lineage from all other living crocodilians.[5] However, although moremorphologically similar toCrocodylidae based on skeletal features, recent molecular studies usingDNA sequencing consistently indicate that the false gharial and by inference other related extinct forms traditionally viewed as belonging to the crocodylian subfamilyTomistominae actually belong toGavialoidea and Gavialidae.[6][7][8]
Fossil dorsal plates of"Tomistoma" calaritanum
Fossils of extinctTomistoma species have been found in deposits ofPaleogene,Neogene, andQuaternary ages inUganda,Italy,Portugal,Egypt andIndia, but nearly all of them are likely to be distinct genera due to older age compared to the false gharial.[9]
The belowcladogram of the major living crocodile groups is based on molecular studies and shows the false gharial's close relationships:[10][11][6][7][8]
^Buffetaut, E. (1982). "Systématique, origine et évolution des Gavialidae Sud-Américains".Geobios.15 (Suppl 1):127–140.doi:10.1016/S0016-6995(82)80107-1.
^Piras, P., Colangelo, P., Adams, D. C., Buscalioni, A., Cubo, J., Kotsakis, T., & Raia, P. (2010).The Gavialis–Tomistoma debate: the contribution of skull ontogenetic allometry and growth trajectories to the study of crocodylian relationships. Evolution & development, 12(6): 568−579.
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