Left humerus, proximal, anterior, posterior, and distal views. A Tympanoctomys aureus B Tympanoctomys barrerae C Tympanoctomys kirchnerorum D Tympanoctomys loschalchalerosorum. bg, bicipital groove; dc, deltoid crest; gt, greater tuberosity; hh, humeral head; le, lateral epicondyle; lec, lateral epicondylar crest; lt, lesser tuberosity; me, medial epicondyle; sf, supratrochlear foramen. Scale bars 5 mm for all views except distal view where the scale bars are 1 mm.