. A descriptive catalogue of the marine reptiles of the Oxford clay. Based on the Leeds Collection in the British Museum (Natural History), London ... Reptiles, Fossil. 174 MARINE EEFTILES OF THE OXFOED CLAT. in height, the decrease continuing to the end of the tail. The zygapophyses are well developed, somewhat concave (or convex) from side to side, and looking more inwards (or outwards) than further forwards. In the caudal region (text-figs. 84, 85) the centra, as already mentioned, are wider than deep; laterally, at least in the young, they bear prominent facets for union with the caudal ri
. A descriptive catalogue of the marine reptiles of the Oxford clay. Based on the Leeds Collection in the British Museum (Natural History), London ... Reptiles, Fossil. 174 MARINE EEFTILES OF THE OXFOED CLAT. in height, the decrease continuing to the end of the tail. The zygapophyses are well developed, somewhat concave (or convex) from side to side, and looking more inwards (or outwards) than further forwards. In the caudal region (text-figs. 84, 85) the centra, as already mentioned, are wider than deep; laterally, at least in the young, they bear prominent facets for union with the caudal ribs, which in the adult become joined to the centra. These ribs are compressed from above downwards, and a little behind the middle of the tail some are considerably expanded towards their outer ends; in all there is a tendency to curve backwards. The facets for the chevrons commence on the second or third caudal; at first they are confined to the hinder part of the centrum, where they form a pair of projections truncated by a flat nearly circular surface looking downwards and backwards. Further back (text-fig. 85) these facets are on both the Text-fig. Posterior caudal vertebrae of Ci-yptodeidus oxoniensis: A, end of caudal series from left side ; B and C, posterior caudal vertebrae from below. ( 3705, | nat. size.) , facet for chevron-bone ; , caudal rib; , neural arch. anterior and posterior edges of the centra, the heads of the chevrons articulating between the successive centra ; the posterior facet is the larger. The neural arches on the caudal region decrease in height gradually from before backwards; the zyga- pophyses disappear about the middle of the tail; the arches of the caudal vertebree are the last to fuse with the centra, and the fusion takes place from before backwards. The chevrons are not well known ; in the young they are little rounded rods of bone with a slightly expanded vertebral extremity. The cervical, sacral, and caudal ribs have al
Size: 2253px × 1109px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectreptile, bookyear1910
