Mylodontoidea

PP = 100, age = 29.46 Mya (26.67–32.60).

The clade is composed of Scelidotheriidae, Mylodontidae and three stem mylodontoid genera, Octomylodon, Octodontotherium and Paroctodontotherium, with this pattern being consistently recovered in all analyses performed in this study. Those three genera are recovered as successive sister groups to ( Scelidotheriidae, Mylodontidae) in analyses with all H, UN_p and some A models. On the other hand, Octodontotherium and Paroctodontotherium are sister taxa and more closely related to ( Scelidotheriidae, Mylodontidae) in MP analyses, and in some A models. In other analyses, using UN_e and other A models, the three genera were recovered as a clade and sister to Mylodontidae or to Mylodontinae, depending on the analysis.

Mylodontoidea was supported by eight synapomorphies (four for both methods and four exclusively for BI): absence of a mediolateral bulge in horizontal ramus of mandible, at toothrow (BI); absence of a medial ridge running along anterior edge of coronoid process; short and deep angular process (BI); condyles at or just above level of toothrow; mandibular symphysis longer than molariform toothrow (BI); snout elevated anteriorly; absence of prominent lateral walls in lacrimal foramen; and dorsal edge of entotympanic with a strong concave curvature in lateral view, with dorsal projection at anterior end (BI).