Data from: A new Pliosaurus species (Sauropterygia, Plesiosauria) from the Upper Jurassic of Patagonia: new insights on the Tithonian morphological disparity of mandibular symphyseal morphology

Abstract.—Most species of the genus Pliosaurus come from the Northern
Hemisphere, however a growing number of new specimens are now available
from the Southern Hemisphere. Here a new species of Pliosaurus is
described, the second for the genus from the Southern Hemisphere,
collected from the upper Tithonian (Jurassic) levels of the Vaca Muerta
Formation, Neuquén Province. Pliosaurus almanzai n. sp. is characterized
by two autapomophies: angular participating in the mandibular symphysis
and occipital condyle without a notochordal pit or several,
irregularly-arranged grooves. Additionally P. almanzai can be
differentiated from other Pliosaurus species by the following characters:
trihedral teeth; nine or more symphyseal alveoli; 15-17 post symphyseal
alveoli; and parasphenoid without ventral keel. Pliosaurus almanzai n. sp.
shows that Pliosaurus species with nine or more 9 symphyseal alveoli
persisted until the late Tithonian, contrary to previous assumptions that
only species with six symphyseal alveoli were present.