. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE TEMPORAL ARCHES OF THE REPTILIA. 1/9 quadratojugal. The quadratojugal has only a slight union with the jugal. The postfrontal joins by its whole length with the parietal. Now, no one will question but that this arrangement of these bones is the primitive one for the reptilia, and any rear- rangement or readjustment must be a secondary result or spe- cialization. Among the higher forms, the nearest approach to this condi- tion is seen in the testudinate skull (Fig. 3), in which the bony roof still remains unpierced ; that
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE TEMPORAL ARCHES OF THE REPTILIA. 1/9 quadratojugal. The quadratojugal has only a slight union with the jugal. The postfrontal joins by its whole length with the parietal. Now, no one will question but that this arrangement of these bones is the primitive one for the reptilia, and any rear- rangement or readjustment must be a secondary result or spe- cialization. Among the higher forms, the nearest approach to this condi- tion is seen in the testudinate skull (Fig. 3), in which the bony roof still remains unpierced ; that is, there is no supra- or latero- temporal fenestra in such forms as Chelone, an undoubted prim- itive type of testudinate skull. The postorbital and postfrontal. FIG. 14. Cynognathus, after Woodward. are not distinct, or one or the other is absent. The prosquamosal has disappeared, or has become fused with some adjacent ele- ment. The quadratojugal has become greatly enlarged, sep- arating the jugal from the quadrate, and articulating above with the squamosal — that is, it has taken the position of the pro- squamosal in the Pareiasaunts skull. It is assumed that the prosquamosal, if present, is fused with the -squamosal, but I fail to see any conclusive evidence of this ; and it would seem more reasonable that, if the element is really present in the testudinate skull, it is fused with the quadratojugal, which has usurped its place and relations. Indeed the loss of the narrow bone on the outer side of the cotylosaurian skull would leave an arrangement pretty similar to that of Chelone, except that the quadrate is partly uncovered. In the posterior part of the skull a vacuity has arisen, or, more. 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Bio
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
