80 UPPER CRETACEOUS TELEOSTS 
The exoccipitals meet in the mid-line of the posterior face of the neurocranium 
both above and below the foramen magnum, completely enclosing it. Ventrally each 
exoccipital forms one dorso-lateral third of the occipital condyle. From the condylar 
region two struts of bone pass outwards, one laterally and one dorso-laterally; the 
lateral strut meets the pterotic, but this is overlain by the superficial intercalar. 
The ventral edge of this strut, near to the condyle, has a large foramen within it. 
This foramen transmitted the vagus nerve and possibly also the glossopharyngeal 
nerve. The dorso-lateral strut meets the epiotic and is continued upwards by 
the latter bone. Lateral to the foramen magnum the exoccipital is pierced by one or 
two very small foramina which appear to have transmitted occipital nerves. On the 
lateral face of the skull the exoccipital forms the postero-dorsal wall of the otolith 
chamber and meets the basioccipital ventrally, the prootic anteriorly, and the 
pterotic dorsally. Dorsally the exoccipital contributes to a large concave depression 
in the cranial wall which served to house musculature associated with the branchial 
apparatus. Internally, in the floor of the foramen magnum, the exoccipitals meet 
in the mid-line to form a shelf. The anterior edge of this shelf forms the posterior 
margin of the fenestra between the otolith chambers and the cranial cavity. 
The intercalar is a moderately large bone incorporated into the cranial wall. It 
forms the main part of the lateral strut from the exoccipital and is wrapped around 
the postero-ventral corner of the braincase. It contacts the pterotic dorsally below 
the hind end of the hyomandibular facet. On the posterior face of the skull the 
intercalar bears a small projection which provided the articulatory region for the 
ventral limb of the post-temporal. 
Hyopalatine bones. A reconstruction of the hyopalatine bones is shown in medial 
view in Text-figure 36. The hyomandibular is relatively deep and robust and is 
vertical in position. The head of the hyomandibular is single and elongate and fits 
into the grooved hyomandibular facet. The opercular process is situated about 
mid-way down the bone. Laterally the hyomandibular bears a shallow crest which 
runs obliquely back from the anterior region of the head of the bone. The anterior 
extent of the bone is considerably thinner and was covered in part by the metaptery- 
goid. 
The quadrate is large, stout and triangular. The condyle is ventral in position 
and is arranged transversely. The posterior region of the upper border bears a deep 
indentation which marks the upper margin of the groove on the medial face of the 
bone which housed the symplectic. The ventral region of the preoperculum rested 
against the posterior edge of the quadrate, which is considerably thickened. The 
anterior quadrate region is indistinct but it appears to be sandwiched between 
posterior extensions of the ectopterygoid, or both the ectopterygoid and the endo- 
pterygoid. 
The ectopterygoid is bent through an angle of about 30° towards its posterior 
end where it overlaps the quadrate laterally. Both the ectopterygoid and endo- 
pterygoid are in the form of elongated laminae, which are fused along their ventral 
edges thus leaving a long dorsal V-shaped trough between them. The ectopterygoid 
is relatively shallow, the endopterygoid being much deeper. Anteriorly the ecto- 
