Boyer diss 2009 1046..

suggests a ventriflexed, abducted proximal carpal row. The pronounced tubercles
delimiting the extensor compartments are consistent with a mobile wrist joint in which
extreme hand postures (primarily extremes of dorsiflexion and abduction) could have
caused the extensor tendons to strain their boundaries if not reinforced by bony
buttresses.
Comparison.—Compared to that of other plesiadapids, the radius of P. cookei is
not remarkable. The radial head is essentially the same shape as it is in the other taxa for
which it is known (Table 4.4A). The distal end is also similar among all taxa for which it
sufficiently known, although it is too fragmentary in both Nannodectes specimens to be
confident in this assessment. The distal end appears to be physiologically supinated (i.e.,
to exhibit torsion) relative to the proximal end to a similar degree in N. intermedius and
P. tricuspidens. The pronator teres tuberosity is equally noticeable in N. intermedius, the
only other specimen for which it is preserved. Two points of interesting variation include
the following: (1) P. cookei has a more gracile radial shaft than those of P. tricuspidens
and N. intermedius (Table 4.4A: SSV) and (2) N. intermedius has a larger radial head for
its shaft length (Table 4.4A: HLV) as compared to either P. cookei or P. tricuspidens.
Ulna
Description.—A nearly complete left and a proximal fragment of the right ulnae
are preserved. Unfortunately, a segment of the shaft of the left side is missing, and the
exact length is unknowable, although it can be estimated using the left radius. This was
done during preparation of the skeleton and the missing segment of the ulna has been
reconstructed with paste epoxy (Fig. 4.5B). Neither side preserves enough of the
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