Mylodontinae Gill, 1872

Mylodontinae Gill, 1872

Indet.

Referred material: First molariform: PIMUZ A/ V 489; upper molariform: PIMUZ A/ V 490; incomplete pelvis: PIMUZ A/ V 500; tibia: PIMUZ A/ V 4099; two fragments of the mandible: PIMUZ A/ V 4101.

Comment: Te specimen PIMUZ A/V 4099 is similar in all respects to the specimen PIMUZ A/V 4147 attributed to Mylodon darwinii Owen, 1839a (see below) with the difference that the two epiphyses are not sufficiently preserved to document the articular facets. Tis alteration of the epiphyses, especially the distal part as it carries the diagnostic elements, limits our identification. Te two mandibular fragments are particularly uninformative, and the specimen shows an unnatural organization of the teeth. I suspect that different pieces were incorrectly assembled. Te one relatively complete tooth could be an mf1 of Mylodon Owen, 1839a ( McAfee, 2009) but I cannot confirm this statement. PIMUZ A/V 489 and PIMUZ A/V 490 correspond to isolated teeth without any particularity except for an oval shape longer than wide, suggesting an attribution to mf1, which could belong to different species of mylodonts. Finally, the specimen PIMUZ A/V 500 is a pelvic girdle too fragmentary to suggest a clear determination (but see Cartelle et al., 2019 for an example of mylodont pelvis girdle). As a precaution, I prefer to propose uncertainty at the ‘subfamilial’ rank to limit questionable interpretations for the specimens mentioned in this section.