. Bulletin - United States National Museum. Science. MIOCENE CALVERT MYSTICETES 113 Figure 47.—Views of left radius, ANSP 12691, of Eschrichtius cephalus Cope: a, internal view; b, view of proximal end. Abbrs.: ant., anterior face; pt., posterior face. its transverse diameter. An indentation on the posterior face of the proximal end marks the location of the articular area for its contact with the ulna. The internal and external faces of the shaft are slighdy convex. Measurements (in mm.) of left radius, ANSP 12691 are as follows: Greatest length, 396; anteroposterior diameter of proxima
. Bulletin - United States National Museum. Science. MIOCENE CALVERT MYSTICETES 113 Figure 47.—Views of left radius, ANSP 12691, of Eschrichtius cephalus Cope: a, internal view; b, view of proximal end. Abbrs.: ant., anterior face; pt., posterior face. its transverse diameter. An indentation on the posterior face of the proximal end marks the location of the articular area for its contact with the ulna. The internal and external faces of the shaft are slighdy convex. Measurements (in mm.) of left radius, ANSP 12691 are as follows: Greatest length, 396; anteroposterior diameter of proximal end, ; transverse diameter of proximal end, ; anteroposterior diameter of distal end, 110; trans- verse of distal end, 53. Ulna.—A large right ulna (USNM 23749) that has the shaft broken off 280 mm. below the horizontal articular surface of the olecranon fossa and a considerable portion of the posterior border of the olecranon process eroded is tentatively referred to this mysticete. This ulna is more massive, larger, and presumably longer than those of all other Calvert Miocene mysticetes and probably belonged to a larger individual than the type. Viewed from the side, the posterior profile is slightly more curved than the an- terior profile. In cross section the shaft is ovoidal and not transversely compressed; the minimum anteroposterior diameter of the shaft is 66 mm., and the minimum trans- verse diameter is 48 mm. The enlarged and thickened olecranon process is bent inward and this curvature modifies the direction of the upper, more vertical portion of the articular surface of the greater sigmoid cavity. The trans- verse diameter of the horizontal articular surface is 64 mm., and the width of the upper articular surface is about 50 mm. Manus.—The position and homologies of the two carpal bones (ANSP 12691) associated with the humerus and radius are uncertain. The preservation of these two in- dicates that some if not all of the five or six carpal
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