The Ichthyosaur has been found in many geological formations like the late Tithonian era Agardhfjellet Formation in Svalbard, Norway that spans the late Jurassic to the Early Cretaceous boundary.
The Agardhfjellet Formation is a geologic formation in Svalbard, Norway. The formation contains the Slottsmya Member, a highly fossiliferous unit (Lagerstatte) where many ichthyosaur and plesiosaur fossils have been found, as well as abundant and well preserved fossils of invertebrates. It preserves fossils dating back to the Oxfordian to Berriasian stages, spanning the Late Jurassic-Early Cretaceous boundary. Tithonian formations In the geological timescale, the Tithonian is the latest age of the Late Jurassic epoch or the uppermost stage of the Upper Jurassic series. Although direct evidence from Slottsmya is currently lacking, the high latitude of this site and relatively cool global climate of the Tithonian suggest that some sea ice was likely present at least in the winter. 
