. Bulletin of the British Museum (Natural History) Geology Supplement. --1 UPPER CRETACEOUS TELEOSTS because of its abdominal pelvic fins cannot be included within the Ctenothrissi- formes. Thus Nematonotus emphasizes the basal convergence of the ctenothrissi- form and myctophiform lineages, and for the time being is best included in the Salmoniformes as a separate suborder, Nematonotoidei. ep3 ep2 pul+ul 5mm Fig. 96. Nematonotus bottae (Davis). Caudal fin skeleton in lateral view. A further genus considered by Woodward (1901) to be a myctophiform is Acro- gnathus. In many respects th
. Bulletin of the British Museum (Natural History) Geology Supplement. --1 UPPER CRETACEOUS TELEOSTS because of its abdominal pelvic fins cannot be included within the Ctenothrissi- formes. Thus Nematonotus emphasizes the basal convergence of the ctenothrissi- form and myctophiform lineages, and for the time being is best included in the Salmoniformes as a separate suborder, Nematonotoidei. ep3 ep2 pul+ul 5mm Fig. 96. Nematonotus bottae (Davis). Caudal fin skeleton in lateral view. A further genus considered by Woodward (1901) to be a myctophiform is Acro- gnathus. In many respects this resembles Sardinioides, notably in respect of the caudal skeleton, but the maxilla, although apparently untoothed, is expanded posteriorly and enters the gape behind the premaxilla. The maxilla also supports two large supramaxillae. The large size of the basal fulcral scales recalls Sardinioides and Aulopus, but not the Ctenothrissiformes in which the fulcral scales are reduced. An adipose fin could not be made out in Acrognathas but the pelvic fins are abdominal. Perhaps Acrognathus is best included with Nematonokis in the suborder Nematono- toidei, which lies very close to the group from which both the Myctophiformes and the Ctenothrissiformes were derived. The last of the Cretaceous genera considered by Woodward (1901) to be a scopeloid is Sardinius. The species Sardinius cordieri von der Marck (Text-fig. 97) certainly shows several myctophiform characters which are comparable with Sardinioides and Aulopus. For instance the maxilla is excluded from the gape, the ascending process is abbreviated (as in Aulopus), the suboperculum is large and the operculum is small, preural vertebra one is fused with ural vertebra one in the caudal skeleton, nnd the neurocranium is 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 t
Size: 1867px × 1338px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
