File:Probainognathian humerus evolution.png

English: Main evolutionary patterns of the humeral structures through the probainognathian evolution. The left humeri are represented in anterior and posterior view. 1, loss of ectepicondylar foramen; 2, hemispherical humeral head; 3, distinct and bony greater tubercle; 4, posteriorly flat trochlea (instead of bulbous ulnar condyle) with deep olecranon fossa; 5, less anteriorly expanded deltopectoral crest with narrow bicipital groove; 6, lesser tubercle smaller than the greater one; 7, posteriorly facing humeral head.. The ectepicondylar foramen is also absent in Boreogomphodon, Trucidocynodon and Probainognathus, but it is not represented in this phylogeny. The ulnar condyle is bulbous posteriorly in multituberculates, but it is not represented in this phylogeny. Abbreviations: b.gr, bicipital groove; cap, capitulum; delt, deltopectoral crest; ect.f, ectepicondylar foramen; gr.tb, greater tubercle; h, humeral head; l.tub, lesser tubercle; ol.f, olecranon fossa; tro, trochlea; ul, ulnar condyle.