Journal of Vertebrate Paleontology

The ichthyosaur Shonisaurus sikanniensis sp. nov. is described from the Pardonet Formation (Norian, Late Triassic) of northeastern British Columbia. The type specimen is considerably larger than Shonisaurus popularis, with an estimated length of 21 m. It also differs from S. popularis in having a fan-shaped scapula, and relatively longer vertebral centra. Studies of this new species, along with re-examination of S. popularis, suggests that Shonisaurus was not as deep-bodied as previously reconstructed. Teeth are set in sockets, but are known only in a few, small individuals. This implies that teeth were present only in juveniles, and that adults were edentulous. The new species extends the geographical and stratigraphical range of Shonisaurus to the middle Norian of British Columbia.

Giant ichthyosaurs of the Triassic—a new species ofShonisaurusfrom the Pardonet Formation (Norian: Late Triassic) of British Columbia