Recently collected materials of a tylosaurine rnosasaur from Haumuri Bluff, New Zealand, are assigned to Taniwhasaurus oweni Hector, 1874. Previously described tylosaurine mosasaur specimens from Haumuri Bluff that were assigned to other taxa are re-evaluated here and assigned to T. oweni. Taniwhasaurus is diagnosed as a tylosaurine based on the possession of a premaxillary rostrum and anterior edentulous process of the dentary. However, Taniwhasaurits also exhibits a prefrontal-maxillary contact in which the prefrontal forms a portion of the naris, thus precluding the frontal-maxillary contact characteristic of all other tylosaurines with the possible exception of Hainosaurus bernardi. The distribution of the frontal-maxillary contact in mosasaurs suggests that it may be correlated with snout elongation.
Caldwell, M. W., Holmes, R. B., Bell Jr., G. L., & Wiffen, J. (2005). An unusual tylosaurine mosasaur from New Zealand: a new skull of Taniwhasaurus oweni (lower Haumurian; Upper Cretaceous). Journal of Vertebrate Paleontology, 25(2), 393–401. https://doi.org/10.1671/0272-4634(2005)025[0393:AUTMFN]2.0.CO;2