. Bulletin of the British Museum (Natural History) Geology Supplement. 72 ELOPIFORM FISHES fahm fuv. asp Whm 30mm par ptfc fica Fig. 36. Protarpon priscus (Woodward). Neurocranium, right lateral view of the otic region. Based on and (formerly ). ventral margin to the post-temporal fossa and at this point the bone bears a promi- nent groove which leads towards, but fails to reach, the occipital condyle. Ventrally the exoccipitals form with the basioccipital a tripartite suture with the first vertebral centrum. This centrum is functionally part of the neurocranium. T
. Bulletin of the British Museum (Natural History) Geology Supplement. 72 ELOPIFORM FISHES fahm fuv. asp Whm 30mm par ptfc fica Fig. 36. Protarpon priscus (Woodward). Neurocranium, right lateral view of the otic region. Based on and (formerly ). ventral margin to the post-temporal fossa and at this point the bone bears a promi- nent groove which leads towards, but fails to reach, the occipital condyle. Ventrally the exoccipitals form with the basioccipital a tripartite suture with the first vertebral centrum. This centrum is functionally part of the neurocranium. The centrum exhibits a shallow, asymetrically placed notochord pit. The outer surface of the centrum is generally smooth save for a few longitudinal grooves on its dorsal half. If, as in the Recent megalopids, a neural arch was attached to this element, its union with the centrum must have been weak since there is no evidence of articulatory facets. A lateral view shows that the neurocranium is deepest at the occiput, a resemblance to Tarpon. The dilatator fossa is shallow and roofed by the pterotic which forms much of its inner wall and floor. The hyomandibular facet slopes ventro-anteriorly, there being a slight downward and lateral flexure at the extreme anterior end. The facet consists of two oval depressions linked by a somewhat narrower groove. Like the dilatator fossa the hyomandibular facet is formed largely by the pterotic. The anterior region of both the facet and the fossa is formed by the autosphenotic which is produced laterally as a weakly developed autosphenotic spine. The subtemporal fossa is large and formed by the pterotic, exoccipital and prootic, which line the dorsal, postero-ventral and antero-ventral regions respectively. It. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museu
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