Boyer diss 2009 1046..

carpals (Figs. 4.7B, 4.9A: 2). Additionally, the shelf-like distally facing facet on the
scaphoid continues ulnarly with morphology of the lunate (Figs. 4.7B, 4.9A: 4). The
radius articular surface of the lunate is also visible in dorsal view (Figs. 4.7B, 4.9A: 6). It
arcs from the radiodistal edge of the lunate, down to the lunate’s proximoulnar margin,
where it contacts the dorsal edge of a small, ulnar facing facet for the distal part of the
distal radial facet of the ulna (Figs. 4.7B, 4.9A: 3). This facet for the ulna can be seen
more clearly from ulnar view. This view also shows that the lunate is mainly nonarticular
on the ulnar side. Its proximal surface has the facet for the ulna. Distal to this
there is a non-articular gap, and farther distal still there is a strip-like facet for the
triquetrum, which faces laterodistally (Fig. 4.7B, 4.9A: 1).
Function.—The morphology of the lunate, like that of the scaphoid, suggests a
habitually dorsiflexed carpus, and the capacity for a large amount of dorsiflexion.
Comparison.—Comparing the lunate described here to that described for N.
intermedius by Beard (1989) (Fig. 4.9A, C), one must conclude that the two bones are
very different. This is surprising given (1) the similarity of the scaphoids of these two
taxa (Fig. 4.8) and (2) the good fit between the scaphoid and the lunate described here.
These two facts begin to suggest that the bone described as the lunate in N. intermedius is
probably incorrectly identified as such, or incorrectly attributed to N. intermedius. Two
observations support the former hypothesis. A bone with nearly identical morphology
was prepared while preserving its association with an intermediate phalanx of USNM
442229 (Fig. 4.9D), strongly suggesting the bone identified by Beard as the lunate does
in fact belong to N. intermedius. However, if this bone is actually the lunate, then the
newly identified element and the originally described one should represent opposite sides
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