. Bulletin. Natural history; Natuurlijke historie. Fig. 10. Axial skeletal components of Corosaurus alcovensis. A, oblique transverse section of midseries cervical vertebra from FMNH PROS showing bicipital ribs; B, ventral view of midseries cervical vertebra with ribs, UW 5485, anterior to top; C, posterior cervical rib from FMNH PR135, anterior to left; D, midseries caudal vertebra, ventral aspect, YPM 41047; E, caudal chevron, YPM 41045; F, typical median gastralium from FMNH PR135; G, typical lateral gastralium from FMNH PR135; H, asymmetrically pronged median gastralium from FMNH PR135; I,
. Bulletin. Natural history; Natuurlijke historie. Fig. 10. Axial skeletal components of Corosaurus alcovensis. A, oblique transverse section of midseries cervical vertebra from FMNH PROS showing bicipital ribs; B, ventral view of midseries cervical vertebra with ribs, UW 5485, anterior to top; C, posterior cervical rib from FMNH PR135, anterior to left; D, midseries caudal vertebra, ventral aspect, YPM 41047; E, caudal chevron, YPM 41045; F, typical median gastralium from FMNH PR135; G, typical lateral gastralium from FMNH PR135; H, asymmetrically pronged median gastralium from FMNH PR135; I, doubly pronged median gastralium from FMNH PR135. facets for these ribs are set upon two short parapophyses lying low on the centrum. The facets are longitudinally oriented and set one above the other. The ribs are distinctly pronged, with both an anterior and a posterior projection lying parallel to the body axis (Fig. IOC). The anterior prong is the largest in the anteriormost ribs; the posterior prong dominates caudally. The atlas/axis complex is poorly known in 'nothosaurs' but is partly preserved in the type of Corosaurus. The spine of the axis differs from those of the other cervicals in being broad and roughly triangular. Its anterior edge overlaps the posterior zygapophysis of the atlas. Pronged, bicipital ribs are present on the axis. The spine of the atlas is very low. Only the neuropophysis of the atlas seems to be preserved, although the nondescript "preatlas" elements of Case (1936, p. 16) may be fragments of the atlas. In any case, the so-called "preatlas" is difficult to evaluate. Dorsal Vertebrae and Ribs The dorsal series is well known through the collection of several strings of ver- tebrae, groups of associated vertebrae, and isolated dorsals which complement the type specimen. I am inclined to accept Case's (1936, p. 15) estimate of six missing dorsal vertebrae from the type for a total of 41 presacrals. If then, 18 vertebrae can be coun
Size: 1882px × 1328px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectnaturalhistory
