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Boyer diss 2009 1046..

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INTRODUCTION<br />

Bloch et al. (2007) analyzed the relationships among plesiadapiforms using a mixture of<br />

species, genus, and family level taxa. They used a family level operational taxonomic<br />

unit (O.T.U.) to represent plesiadapids and based their coding primarily on the literature<br />

available for the skull and skeleton of Plesiadapis tricuspidens (e.g., Russell, 1964;<br />

Szalay et al., 1975; Gingerich, 1976), a humerus of Plesiadapis walbeckensis (Szalay and<br />

Dagosto, 1980), and the postcranium of Nannodectes (Simpson, 1935; Beard, 1989), as<br />

well as on direct observations of the skeleton of Plesiadapis cookei (UM 87990). When<br />

different reference species showed variance in character states, Bloch et al. (2007)<br />

represented the Plesiadapidae as polymorphic. New information on plesiadapid skeletons<br />

presented in chapters 2-4 allows a more accurate coding of the “Plesiadapidae” in the<br />

Bloch et al. (2007) matrix. In this study, the use of polymorphic codings for the<br />

“Plesiadapidae” is avoided as much as possible: a “composite” Plesiadapidae O.T.U. is<br />

generated by optimizing states of characters onto the ancestral node of a newly generated<br />

species level tree.<br />

The over arching hypotheses to be tested with the new skeletal material are that<br />

(1) plesiadapids are close relatives of carpolestids and (2) these taxa plus saxonellids and<br />

Chronolestes simul are the sister taxon to Euprimates. The former hypothesis is an<br />

apparently fragile aspect of recent phylogenetic analyses (Bloch et al., 2007). While a<br />

carpolestid-plesiadapid clade has been favored by specialists familiar with dental<br />

morphology (Simpson, 1937; Szalay, 1968; Gingerich, 1976; Fox, 1993; Van Valen,<br />

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