Boyer diss 2009 1046..

17379, still attributed by them to “P. gidleyi” (p. 152, fig. 9. III.A-E, IV.A-E). This same
figure also includes the astragalus and calcaneum of the primitive arboreal treeshrew
Ptilocercus lowii. The intent of the figure design is not explicitly stated, but presumably it
is meant to illustrate two different taxa, which come close to Szalay’s view of the
“archontan morphotype.” Szalay and Drawhorn also illustrated tarsals of P. tricuspidens
(MNHN R 610-611: p. 159, fig. 11. III.A-E, IV.A-E) next to tarsals of Cynocephalus
volans. Why Szalay and Drawhorn chose to re-illustrate the calcaneum MNHN R 611
(see above), but not the astragalus MNHN R 5347, is not stated. There do appear to be
differences between MNHN R 610 and MNHN R5347 (see below), but Szalay did not
mention any of these or what they might mean. Furthermore, I could not find a reference
to Szalay and Drawhorn’s figure 11 in their text, but presumably the intent of the figure
was to illustrate similarity between Plesiadapis and Cynocephalus. Szalay and Drawhorn
(1980) argued that Cynocephalus has mobility in its ankle joint to an extreme that is only
of use in arboreal settings.
Szalay and Dagosto (1980) provided a more detailed functional assessment of the
plesiadapid and plesiadapiform distal humerus than previously given. The work is
elegant in its assessment of functional properties using qualitative comparative
morphology combined with quantitative comparisons. These authors provided the first
illustrations of a humerus of P. walbeckensis (the existence of which was first mentioned
in Szalay et al., 1975) from the Walbeck fissure fillings (p. 10, fig. 3). Walbeck is
roughly correlative with Ti2-3 (Gingerich, 1976; Gradstein et al., 2004). The authors do
not provide a catalogue number for the specimen. Szalay and Dagosto (1980) described a
second “archontan” from the Mason Pocket locality (AMNH 89519) but then suggested
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