Researches on the Structure, Organization, and Classification of the Fossil Reptilia VII Further Observations on Pareiasaurus . he scapula. The coracoid appears to have formed a wide, flattened base upon which the weight 336 PROFESSOR H, G. SEELEY OK THE STRUCTURE, ORGANIZATION, of the shoulder girdle was supported. It is possible that the specimen is imperfect atthe base since the bone is there 2\ inches thick, and narrows anteriorly. The posteriorhalf of the coracoid forms the great semi-cylindrical concavity for the humerus, whichis notched at the basal margin, both in front and behind, but
Researches on the Structure, Organization, and Classification of the Fossil Reptilia VII Further Observations on Pareiasaurus . he scapula. The coracoid appears to have formed a wide, flattened base upon which the weight 336 PROFESSOR H, G. SEELEY OK THE STRUCTURE, ORGANIZATION, of the shoulder girdle was supported. It is possible that the specimen is imperfect atthe base since the bone is there 2\ inches thick, and narrows anteriorly. The posteriorhalf of the coracoid forms the great semi-cylindrical concavity for the humerus, whichis notched at the basal margin, both in front and behind, but marked inferiorly by anelevated border, similar to the edge of the scapular part of articulation. The bonebecomes rapidly thinner in front, so that at the anterior border, which is convex inoutline, the thickness is more than half an inch, and it is thin toward the junctionwith the precoracoid. It terminates toward the interclavicle in a sharp border,rounded from above downward. There is no certain evidence whether it met theinterclavicle at the margin, or passed behind it as in Ichthyosaurus* The clavicular arch Fig. 4> Clavicular arch of Pareiasaurus Baini, seen from the front, in natural union with the shoulder girdleas found, ic. interclavicle, cl. clavicles, sc. scapula, pc. precoracoid, cor. coracoid,/. foramen. consists of a clavicle, interclavicle, and epi-clavicle. The interclavicle (ic.) is a strongT-shaped bone, broadly expanded at the superior transverse bar, and giving attachmentupon this flattened surface to the clavicles (cl), which extend outward and backward ina curve to the scapulae (sc). There is no indication that the clavicle was embedded inthe interclavicle in the way shown in P. bombidens. The transverse bar of the inter-clavicle measures round the convex curve 19 inches ; its median depth, as preserved,in about 9 inches. The interclavicle was prolonged downward and backward in aflat, wide, median bar, comparable to that seen in .the interclavicle
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Keywords: ., bookauthorseeleyh, bookcentury1800, bookdecade1890, bookyear1892
