Boyer diss 2009 1046..

Figure 6.1. CT reconstruction of Plesiadapis cookei’s skeleton (UM 87990) in
antipronograde posture with life reconstruction superimposed below it. The purpose of
placing the skeleton in this posture on a branch of such girth and orientation is to provide
a summary of results of analyses and comparisons: P. cookei and other plesiadapids were
better suited to cling and climb on large diameter supports than small ones, given the
configuration of their limb joints. All known plesiadapids probably used pronograde,
orthograde, and antipronograde postures on large trees trunks and branches. However,
aspects of P. cookei’s skeleton suggest that it may have used antipronograde postures
more frequently than others. Perhaps it even used suspensory postures sometimes. Study
of the dentition reconstructs P. cookei as folivorous, but leaves do not typically grow
directly from tree trunks, like that in the figure. P.cookei probably used pronograde and
orthograde postures when resting or traveling on large tree trunks or branches. When
foraging, it must have ventured out into the terminalia of branches where leaves grow.
As it progressed to narrower and narrower branches it probably assumed antipronograde,
and then suspensory postures. I thank P. Gingerich who gave me this synthetic
perspective at my dissertation defense. In the picture, one may imagine that P. cookei is
returning from, or venturing to engage in a bout of foraging and feeding. The life
reconstruction is a photoshop generated image. I sampled photographs of pelage of
lemurs, and rodents to create that of P. cookei. The bushy tail is based on that preserved
for P. insignis.
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