Figure 18 in Description of a new long-snouted beaked whale from the Late Miocene of Denmark: evolution of suction feeding and sexual dimorphism in the Ziphiidae (Cetacea: Odontoceti)

Figure 18. Illustration of the difference of development of the prominence posterior to the nasals on the vertex in dorsal view in: A and B, Mesoplodon perrini (USNM 504260); C and D, Mesoplodon layardii (USNM 550150); E and F, Mesoplodon grayi (SNM CN1); and G and H, Berardius bairdii (USNM 550886). The prominence is outlined in B, D and F. Scale bar = 10 mm.