Fig. 2 in New Morphological Evidence for the Phylogeny of Artiodactyla, Cetacea, and Mesonychidae

Fig. 2. Representative morphologies for the lingual margin of P4. Labial is toward the top of the page, anterior is to the left, and the scale bars represent 10 mm. A. The third and fourth upper premolars of the artiodactyl Elomeryx armatus (AMNH 582). Note the presence of a prominent entocingulum that nearly encircles the base of the protocone. An entocingulum on P4 is widely distributed among basal artiodactyl taxa; therefore, it is a potential synapomorphy of Artiodactyla. B. The third and fourth upper premolars of the mesonychid Harpagolestes orientalis (AMNH 26300). Note the complete absence of an entocingulum on P4. Abbreviations: en, entocingulum; P3, upper third premolar; P4, upper fourth premolar.