[N] 2003 Temnodontosaurus
The temporal region in Temnodontosaurus trigonodon and Temnodontosaurus platyodon consists of three discrete ossifications. These bones are identified as the supratemporal, bordering much of the temporal opening, and in mid-cheek, the squamosal, which is in contact with the quadratojugal along its ventral margin. Interpretation of the bone in mid-cheek position as a neomorphic \\\"supernumerary\\\" ossification is rejected. The supratemporal bone of ichthyosaurs is functionally convergent with the squamosal of diapsids. The size and configuration of the supratemporal casts doubt on the supposition that ichthyosaurs were diapsids.
Maisch, Michael W. & Axel Hungerbühler, 2003? (2001). New Evidence for a Discrete Supratemporal Bone in the Jurassic Ichthyosaur Temnodontosaurus. Historical Biology: A Journal of Paleobiology 15 (4): 335 - 345