. Bulletin of the British Museum (Natural History), Geology. 428 CERTAIN TRIASSIC AND LIASSIC PH OLI DOPHOR I D AE the ganoin covering of the exoskeletal cranial bones and body scales has started independently (as probably in many other lines of evolution), in the Pholidophorus series from scales with a smooth posterior margin, in the Pholidophoroides series from scales with a pectinated or serrated hind margin. The general phylogenetic evolution can of course be elucidated from other features also, but the material investigated is too fragmentary to illustrate this in great detail. Some indic
. Bulletin of the British Museum (Natural History), Geology. 428 CERTAIN TRIASSIC AND LIASSIC PH OLI DOPHOR I D AE the ganoin covering of the exoskeletal cranial bones and body scales has started independently (as probably in many other lines of evolution), in the Pholidophorus series from scales with a smooth posterior margin, in the Pholidophoroides series from scales with a pectinated or serrated hind margin. The general phylogenetic evolution can of course be elucidated from other features also, but the material investigated is too fragmentary to illustrate this in great detail. Some indications may perhaps be worth noting. The sensory pit-lines seem to show a tendency towards a successively more super- ficial position and consequently their markings on the underlying bones become successively less pronounced. The supramaxillary (horizontal) and postmaxillary. u to in < t- O Porasemlonotidoe, represented by Parasemionotus labordei Fig. 16. Diagram illustrating the writer's opinion concerning phyletic relationships between certain genera and species of the family Pholidophoridae s. str., based on the condition of the preoperculum ; within the rectangle are species with thin, cycloid scales. The possible derivation of the family from the parasemionotids is indicated by the preoperculum of Parasemionotus labordei (Lehman 1952, text-fig. 116). Further explanation in the 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: 2150px × 1162px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
