New paper on Plesiadapis suffers from taxon exclusion

Boyer and Gingerich 2019
bring us an excellent and comprehensive review of Plesiadapis (Figs. 1-3), a rodent relative (clade: Glires, Figs. 4, 5) traditionally and wrongly considered a basal primate with rodent-like teeth.

Figure 1. From Boyer and Gingerich 2019, Plesiadapis skeleton and in vivo.

Figure 1. From Boyer and Gingerich 2019, Plesiadapis skeleton and in vivo.

This primate-mimic
nests with another primate mimic, Daubentonia (Fig. 3), the extant aye-aye, a taxon barely mentioned and not analyzed by Boyer and Gingerich.

Plesiadapis

Figure 2. Plesiadapis, formerly considered a basal primate, is here considered a member of Glires close to Carpolestes and Daubentonia. See figure 3.

From the abstract
“Plesiadapis cookei is a large-bodied plesiadapiform euarchontan (and potential stem primate) known from many localities of middle Clarkforkian North American Land Mammal age, late Paleocene epoch, in the Clarks Fork Basin of northwestern Wyoming.”

Figure 1. Ignacius and Plesiadapis nest basal to Daubentonia in the LRT.

Figure 3. Ignacius and Plesiadapis nest basal to Daubentonia in the LRT.

From the abstract
“On a broader scale, cladistic analysis of higher-level taxa… indicates that plesiadapids and carpolestids exhibit a greater number of identical character states than previously thought … Even so, analysis of combined data from dentition, cranium, and postcrania still robustly support a link between plesiadapids, saxonellids, and carpolestids (Plesiadapoidea) and does not contradict previous hypotheses suggesting a special relationship of plesiadapoids to euprimates (Euprimateformes).”

Figure 4. From Boyer and Gingerich 2019, cladograms nesting Plesiadapis.

Figure 4. From Boyer and Gingerich 2019, cladograms nesting Plesiadapis. Too few taxa. Where is Daubentonia? Where are the derived rodents and multitubercuates? Compare to figure 5.

Too few taxa,
alas is the one obvious issue with Boyer and Gingerich 2019 (Fig. 4).

Figure 1. Subset of the LRT focusing on Glires and subclades within.

Figure 5. Subset of the LRT focusing on Glires and subclades within.

Not much else to say.
The large reptile tree (LRT, 1583+ taxa; subset Fig. 5) is an online resource that can and should be employed. Current traditions and textbooks are out of date on this subject. At least consider the taxon list in your more focused studies so you don’t overlook any obvious taxa. Test them yourselves. Don’t make the same mistake.


References
Boyer DM and Gingerich PD 2019. Skeleton of Late Paleocene Plesiadapis cookei (Mammal, Euarchonta): life history, locomotion, and phylogenetic relationships. University of Michigan Papers on Paleontology 38:269pp.

wiki/Plesiadapis

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