Boyer diss 2009 1046..

even more pronounced. The distal end of MC V shows torsion relative to the proximal
end so that its ventral surface faces slightly radially.
The “set 2” MC V is represented by the complete right side element and the
proximal end of the left (Fig. 4.15; Fig. 4.16D). It is similar to the “set 1” MC V. The
two bones differ in that the “set 2” MC V is longer and more gracile, it has a larger
surface area for the hamate (7.5 mm 2 ), it does not show the dramatic ulnar flaring of the
distal part of the shaft; and does not show the extreme asymmetry in the distal end
profile.
Assessment of metacarpal association and attribution.—Comparative specimens
allow a formulation of a hypothesis on which particular metacarpals of UM 87990
comprise a set belonging to the same animal and further, which set belongs to P. cookei.
Specifically, comparative specimens utilized include MC I, III, and V of N. intermedius;
MC I and III of N. gidleyi; MC III-V of P. tricuspidens; and MC I, III, and IV of P. n. sp.
[new species of Plesiadapis from the Le Quesnoy locality discussed by Youlatos and
Godinot (2004), currently being prepared for formal diagnosis by M. Godinot]. The
starting point for this analysis was assessment of which of the two MC V morphs is most
likely to represent that of P. cookei. Principal coordinates analysis of size standardized
measurements (Table 4.11; Fig. 4.17) reveals that the “set 1” morph is much more similar
to the three MC V’s of P. tricuspidens than is the “set 2” morph. This result allows
confident attribution of the set 1 MC V to P. cookei. Next, two pieces of information
suggest that MC III of “set 1” is more likely to be that of P. cookei than the “set 2”
morph. First, the ratio of P. tricuspidens’ MC III (MNHN R 5295) to its MC V (average
of MNHN R 5305 and a second unnumbered specimen) is 1.31. This value is closer to
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