Figure 21. short side peaks differentiated margin Doyle et al. 1974. 21.1.1 and 21.2.1. Upper crown (transmitted light) view; GSC 124547and 124548; scale bar = 0.5 mm. 21.3.1 and 21.4.1. ?short side peaks differentiated margin. 21.3.1. Specimen with damaged anterior margin but showing three crown ridges and a small anterior mesial protrusion; GSC 124549, scale bar = 0.3 mm. 21.4.1. Showing minor lateral cusp development; GSC 124550, scale bar = 0.5 mm.