Saniwa ensidens from the Green River Formation (Miocene, 48mya, 1.3m length, Leidy 1870, Rieppel and Grande 2007, FMNH PR 2378) is a basal varanid. It nests close to the Varanus/Tylosaurus split. It had long pterygoid teeth (in red).

Conrad J, Rieppel O, Grande L 2008. Re-assessment of varanid evolution based on new data from Saniwa ensidens Leidy, 1870 (Squamata, Reptilia). American Museum Novitates 3630: 1–15. doi:10.1206/596.1.

Leidy J 1870. (Descriptions of Emys jeansesi, E. haydeni, Baëna arenosa, and Saniwa ensidens). Proceedings of the Academy of Natural Sciences of Philadelphia 1870: 123–124.

Rieppel O and Grande L 2007. The anatomy of the fossil varanid lizard Saniwa ensidens Leidy, 1870, based on a newly discovered complete skeleton. Journal of Palaeontology 81 (4): 643–665. doi:10.1666/pleo0022-

wiki/Saniwa