Excavations of ACb-3 Cave have uncovered the remains of at least seven individual Megalonyx jeffersonii, providing the most complete ontogenetic sequence of the taxon from one locality. Four individuals representing four distinct age classifications (infant, juvenile, subadult, and adult) were described and examined for pathologies. Cranial and major forelimb elements depict a change in morphology (trending from robust and stout to gracile and elongate) through ontogeny. Pathologies on the scapula and radius of the adult ground sloth indicate a potential attack from fighting or mating. The presence of infant and juvenile sloths suggests this cave may have been used as a maternity den. The nearly complete adult (RMM 5353) was compared to Megalonyx from other North American localities. Bivariate plots, created using linear measurements, showed that RMM 5353 was within the size range of M. jeffersonii and further supports the concept of Megalonyx chronospecies.

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