A new mosasaur, Eremiasaurus heterodontus, gen. et sp. nov., from the Maastrichtian phosphates of Morocco is described based on the basis of two specimens: one consisting of a nearly complete skull, vertebral column, and isolated appendicular elements, and the other a nearly complete skull with associated vertebral column. This new mosasaur exhibits a high degree of heterodonty and a large number of pygal vertebrae, the latter feature expressed to a greater degree only in Plotosaurus from the Maastrichtian of California. Analysis of a data matrix of 135 characters and 32 terminal taxa resulted in three equally most parsimonious trees, and recovered E. heterodontus as the sister taxon to Plotosaurini. A second analysis incorporating five species of the globidensine mosasaur Prognathodon recovered 252 most parsimonious trees. This second analysis also recovered E. heterodontus as the closest relative to the Plotosaurini, a position supported by the presence of an internarial bar keel, exclusion of the prefrontals from the narial borders, narial embayments in the frontal, and the presence of a quadrate ala groove. A change in the positions of several key character-state changes in the second analysis not only supports the exclusion of E. heterodontus from the globidensine mosasaurs, but also calls into question the monophyly of the Globidensini and the suite of quadrate and dental characters used to diagnose this group.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.