Adaptive radiation of the early evolution of ichthyosaurs

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Work for the past three years has focused on the incredibly rich fossil faunas of marine reptiles in the Triassic rocks of northeastern British Columbia, Canada. This region has over 1200 m of continuous Triassic marine sedimentation, spanning the Early, Middle and Late Triassic. It is during the Triassic that tetrapods first returned to the sea and diversified in the marine realm. Consequently, it is a particularly important time interval in the study of marine reptiles. This study has involved the collection and preparation of new fossil material, and the comparative study of critical collections in other institutions. Our work was concentrated primarily in two horizons - the Lower and Middle Triassic Sulphur Mountain Formation at Wapiti Lake, and the Upper Triassic Pardonet Formation in the Pink Mountain area. The overall results of this grant have been extensive. Over 140 fossil vertebrate specimens were collected, which are being prepared and studied. One of these, a 23m ichthyosaur, is the largest marine reptile known in the fossil record. Two scientific papers on this work have already been published (Motani et al, 1998 ; Nicholls and Manabe, 1998). Two papers have been presented at professional meetings (Nicholls and Manabe, 1999a, 1999b). Five more scientific papers are in progress, and will result as study and preparation of the specimens proceeds.