Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/127

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1869.]
HUXLEY—TRIASSIC DINOSAURIA.
41

so-called "scapula" (tab. x. fig. 7) looks to me very much like the ischium; but the figure is not of such a character as to allow me to speak with confidence on this point. Putting the information yielded by these two skeletons together, it proves the existence in the Upper Trias of Stuttgart of a Dinosaurian of great size.

The sixty vertebræ which he in uninterrupted series in the specimen A, occupy a length of seventeen Württemberg feet. Thirty- seven of these vertebræ form a tail eight feet long. Two (more probably three) vertebræ in the sacrum take up a foot, while the twenty-one præsacral vertebræ form a series 7 feet long. The centrum of the last caudal vertebra is 1⋅5 in. long, and rather less than 1 in. in vertical height of the articular surface; and the tail is not complete. The middle caudal vertebræ have centra 2⋅5 in. long, with a height of 1⋅25 in. Further towards the sacrum the centra are 4 inches high and 3 inches long. The hindermost of the præsacral vertebræ have the articular surface of the centra 6 inches wide, and are from 5 to 6 in. long. They diminish in size forwards; and the five most anterior, which together occupy 2 feet, have about the dimensions of the middle caudal vertebræ. The centra are all constricted in the middle of their length, and have slightly concave articular surfaces. The articular faces of the centra are almost circular in contour. The spinous process is flat, quadrangular, 3⋅4 in. high, 4⋅5 in. long. It follows from this account that the two cervical vertebræ of the specimen B, which are opisthocœlous, must have had their place in front of the twenty-one præsacral vertebræ shown to exist by A and as neither of these is axis or atlas, there must have been, at fewest, twenty-five præsacral vertebræ, which is one more than exists in a crocodile. But as the tubercular transverse processes of the cervical vertebræ in question arise low down in their arches, and the capitular processes lie below the middle of the centrum, they may well be anterior cervicals. The characters of the dorsal vertebræ, as shown by the two consecutive series of five and eight respectively in B, are very singular, and in some respects anomalous.

The sacrum is unlike that of other Dinosauria, in possessing only two completely ankylosed vertebræ. On the other hand, the expansion and coalescence of the sacral ribs at their extremities is characteristically Dinosaurian, No chevron bones are described or figured.

One of the most remarkable portions of the skeleton A is an oblong plate of bone, nearly two feet long, and having apparently half that width, with edges which vary from one to three inches in thickness. The anterior external angles are prolonged into stout processes, which are directed upwards and inwards and are somewhat re- curved. Professor Plieninger considers this bone to be the sternum; and I see no reason for dissenting from his interpretation. A Rhea of the same size as the triassic Dinosaurian would present a sternum of very similar proportions, especially as regards the antero-lateral or pleurosteal processes.

The scapula of B has a length of 21 inches. It is long and narrow. The coracoid is short and rounded, as in other Dinosauria. The humerus of A is rather more than 17 inches long; but that of B