Shonisaurus is a genus of very large ichthyosaurs. At least 37 incomplete fossil specimens of the type species, Shonisaurus popularis, have been found in the Luning Formation of Nevada, USA. This formation dates to the late Carnian-early Norian age of the Late Triassic, around 227 million years ago.[3] Other possible species of Shonisaurus have been discovered from the middle Norian deposits of Canada and Alaska.[2][4]
^ abNicholls, Elizabeth L.; Manabe, Makoto (2004). "Giant Ichthyosaurs of the Triassic—A New Species of Shonisaurus from the Pardonet Formation (Norian: Late Triassic) of British Columbia". Journal of Vertebrate Paleontology. 24 (4): 838–849. doi:10.1671/0272-4634(2004)024[0838:GIOTTN]2.0.CO;2. ISSN0272-4634.
^Balini, M.; Jenks, James F.; Martin, R.; McRoberts, Christopher A.; Orchard, Michael J.; Silberling, Norman J. (2015). "The Carnian/Norian boundary succession at Berlin-Ichthyosaur State Park (Upper Triassic, central Nevada, USA)". Paläontologische Zeitschrift. 89 (3): 399–433. Bibcode:2015PalZ...89..399B. doi:10.1007/s12542-014-0244-2.
^Adams, Thomas L. (2009). "Deposition and taphonomy of the Hound Island Late Triassic vertebrate fauna: Fossil preservation within subaqueous gravity flows". PALAIOS. 24 (9): 603–615. Bibcode:2009Palai..24..603A. doi:10.2110/palo.2009.p09-010r.