A new genus and species of Planopinae (Xenarthra: Tardigrada) from the Miocene of Santa Cruz Province, Argentina.

Prepoplanops boleadorensis, a new genus and species of Planopinae (Xenarthra, Tardigrada), is described herein. The new taxon is based on a nearly complete specimen recovered from the Cerro Boleadoras Formation (Miocene, Rio Zeballos Group), in northwestern Santa Cruz Province, Argentina. The shape and length of the predentary region of the skull and the length of the diastema of Prepoplanops boleadorensis differ from those present in the species of Planops. The posterolateral opening of the mandibular canal and the position of the posterior margin of the mandibular symphysis differ from those of species of Prepotherium. In addition, Prepoplanops boleadorensis differs from Planops martini in the size of the humeral tuberosities, the development of the deltoid crest, the position of the distal margin of the humeral trochlea, the shape and position of the olecranon, the development of the femoral epicondyles, and the shape of the medial margins of the patellar trochlea and medial condyle. On the other hand, it differs from Prepotherium potens in the shape of the medial margin of the medial condyle. The recognition of Prepoplanops boleadorensis increases the diversity of Planopinae for the Miocene of Patagonia, Argentina.