. Bulletin of the British Museum (Natural History), Geology. REVISION OF ACTINOPTERYGIAN AND COELACANTH FISHES 321 bone I think that this is a compound ossification incorporating the parietal and extrascapular (or the post-temporal of Traquair, 1879, pi. 4; White, 1932 : 82). The digitate prominence behind the parietal (X of Woodward, 1918, pi. 14, fig. 4) seen on many of the other Pycnodonts, possibly represents the vestiges of the supra- scapular. This prominence has not been observed on any of the four specimens of this species, because the preservation in that area is poor. Beneath the par
. Bulletin of the British Museum (Natural History), Geology. REVISION OF ACTINOPTERYGIAN AND COELACANTH FISHES 321 bone I think that this is a compound ossification incorporating the parietal and extrascapular (or the post-temporal of Traquair, 1879, pi. 4; White, 1932 : 82). The digitate prominence behind the parietal (X of Woodward, 1918, pi. 14, fig. 4) seen on many of the other Pycnodonts, possibly represents the vestiges of the supra- scapular. This prominence has not been observed on any of the four specimens of this species, because the preservation in that area is poor. Beneath the parietal is a large dermopterotic (supratemporal—intertemporal of earlier workers) which borders the parietal ventrally. It is a deep four-sided plate tapering sharply forward above the orbit and forming part of its border. Posteriorly it has a long free border. Fig. 51. Eomesodon liassicus (Egerton). Restoration of skull in lateral view. under which the supracleithrum lies. Beneath the dermopterotic is a much smaller rectangular plate separating it from the opercular and preopercular proper. This plate clearly belongs to the preopercular series since a continuation of the main preopercular canal runs through its anterior edge. In this respect Eomesodon resembles Bobasatrania and some of the Platysomids. The skull roof in front of the supraoccipital is composed of a pair of large frontals which are the largest bones of the skull. Traces of the sensory canal can be seen on them. They are expanded posteriorly, forming the antero-dorsal border of the orbits ; and anteriorly they taper to meet another ossification which I have called the postrostral. Anteriorly the postrostral reaches the paired premaxillae. These. 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 Museum (Natural History). London : BM(NH)
Size: 1617px × 1546px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
