FIG. 4 in The anatomy and relationships of Piscobalaena nana (Cetacea, Mysticeti), a Cetotheriidae s.s. from the early Pliocene of Peru

FIG. 4. — Piscobalaena nana, dorsal view of the skull of four individual to show the size individual variation within the species: A, "old juvenile" or sub-adult (MNHN SAS 1616); B, adult (MNHN SAS 1617); C, adult (MNHN SAS 1618); D, old adult (MNHN SAS 1623). Scale bar: 20 cm.