Ahytheriini

Casali, Daniel M, Boscaini, Alberto, Gaudin, Timothy J & Perini, Fernando A, 2022, Reassessing the phylogeny and divergence times of sloths (Mammalia: Pilosa: Folivora), exploring alternative morphological partitioning and dating models, Zoological Journal of the Linnean Society 196 (4), pp. 1505-1551 : 1527

Ahytheriini

PP = 100, age = 4.44 Mya (1.93–6.98).

This clade, composed of the intertropical megalonychids Australonyx , Ahytherium , Megistonyx , Nohochichak and Xibalbaonyx , was consistently recovered in all of our analyses, with two alternative arrangements: ( Australonyx , (( Ahytherium , Megistonyx ), ( Nohochichak , Xibalbaonyx ))) in all BI analyses and in par_EW, and ( Australonyx , ( Xibalbaonyx , ( Nohochichak , ( Ahytherium , Megistonyx )))) for IW parsimony analyses. Ahytheriini was supported by 23 synapomorphies (13 for both methods and ten exclusively for BI): absence of fossa on palatal surface of maxilla posterior to Cf1; circular Mf1 cross-section (BI); ascending ramus of mandible partially covers posterior teeth in lateral view (BI); coronoid process not hooked posteriorly (BI); posterior external opening of mandibular canal opens anterolaterally, on ascending ramus; high and narrow braincase (BI); nasal uniform width in its posterior half, lateral margins parallel (BI); interpterygoid and posterior interpalatine regions of roughly equal width (BI); large sinus in pterygoid; ventrally situated infraorbital canal; absence of alisphenoidparietal contact (BI); presence of a marked postorbital constriction; postorbital process of frontal roughly at the level of maxillary foramen (BI); triangular occiput in posterior view (BI); occipital condyles situated well dorsal to the dentition (BI); anteromedially orientation of entotympanic (BI); weakly marked brachiocephalicus crest of humerus (BI); humeral head almost hidden behind the tubercles; anconeal process of ulna not extended anteriorly, not overhanging trochlear notch; widest extension of pronator ridge at the proximal half of radial diaphysis (BI); proximal half of femur narrower than distal half; intermediate tibial length, more than two times the width, but less than three times; and fusion of metatarsal I with entocuneiform.