handleyi, a large surface of the petrosal bone (including the sulcus of the prootic sinus) is exposed through the anteroposteriorly elongated subsquamosal foramen.
These three species share the following three morphological traits that have yet to be analyzed in a broad phylogenetic context: 1) at least in males, all three species have both anterior and posterior accessory cusps on their upper canines; 2) the subsquamosal foramen is anteroposteriorly elongated, exposing a large area of the petrosal bone behind the sulcus of the prootic sinus; and 3) the postglenoid foramen runs posteromedially so that the sulcus of the prootic sinus is not exposed in ventral view.
Anterior portion of parasphenoid cartilaginous, covering vomer; posterior portion of parasphenoid in contact with prootic and basioccipital.
Anterior portion of parasphenoid cartilaginous and covering posterodorsal surface of vomer; posterior portion of parasphenoid in contact with prootic and basioccipital.
Peculiar, large 'auditory foramen', which is usually an ovoid opening on the ventral face of the
prootic through which the utricular otolith is visible.
In the present paper, I intend to explore four potential synapomorphies--(1) the epiotic flange mentioned by Lynch (1996), (2) the fusion of the frontoparietal and prootic mentioned by Lynch (1971), (3) wide separation of the vomers, mentioned by Lynch (1971), and (4) a median notch of the vomer, not mentioned to date.
My restudy of these specimens reveals the suture between the frontoparietal and exoccipital but no suture between the frontoparietal and prootic.
Prootics and exoccipitals fused; entire posterior end of skull well ossified; optic foramina ventrally marginated by cartilage; oculomotor foramina marginated anteroventraly by cartilage;
prootic and jugular foramina with bony margins; with small bony knob formed below epiotic eminences above occipital condyles.
It bears a pair of ascending flanges, which suture with the pterosphenoids and
prootics.
The frontoparietals do not bear crests and are not fused to the
prootics or exoccipitals.
It bears a pair of salient ascending flanges, which suture with the pterosphenoids and
prootics.
