Boyer diss 2009 1046..

medial side facet on MT IV from a ventrally placed one. As for dorsal facets, the
ventrally placed facet is larger than the corresponding medial side facet on MT III. The
lateral side of the proximal end of MT IV differs from that of MT III in having a
continuous concave articular surface for the more lateral metatarsal (MT V) with no
nonarticular gaps separating it into dorsal and ventral regions.
In most respects the proximal end of the “set 2” MT IV is similar to that of the
“set 1” element. However, it is diagnostically different in the morphology of the medial
side, dorsal facet for MT III. Specifically, this facet is larger and strongly concave in the
“set 2” MT IV (instead of slightly convex). As a result of these differences in articular
surface morphology, the “set 2” MT IV, which is a left side element, will not articulate
securely with the left side MT III.
Metatarsal V description.—Only a proximal fragment of the right MT V is
preserved (Fig. 4.40B). It is identifiable as MT V by its large peroneal tuberosity.
However, it clearly did not belong to P. cookei, as revealed by MT V’s preserved with
two other plesiadapid skeletons (Table 4.23). Although not described by Beard (1989), a
proximal base and distal shaft of an MT V of Nannodectes intermedius USNM 442229
are preserved. A specimen of cf. P. churchilli (SMM P77.33.517) from Wannagan Creek
in North Dakota also preserves this element (Fig. 4.39B, C). The plesiadapid MT V is
revealed to be treeshrew or dermopteran-like by these specimens. The UM 87990 MT V
does not fit this pattern and does not even articulate well with the “set 1” MT IV.
Presumably, it articulates with the “set 2” MT IV better, however the MT V facet on MT
IV is too broken to assess this possibility.
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