''Tranatocetus'' is an extinct genus of mysticete from the late Miocene (

Tortonian The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Tort ...

) of Jutland, Denmark. The type and only species is ''Tranatocetus argillarius''.

Description

''Tranatocetus'' is similar to ''"Aulocetus" latus'', ''"Cetotherium" megalophysum'', ''"Cetotherium" vandelli'', '' Mesocetus'', and '' Mixocetus'' in having rostral bones that override the frontals and contact the parietals, nasals dividing the maxillae on the vertex, a dorsoventrally bent occipital shield with a more horizontal anterior portion and more vertical posterior portion, and a tympanic bulla with short, narrow anterior portion with rounded or squared anterior end and wider and higher posterior portion that is particularly swollen in the posteroventral area. Like other tranatocetids, the skull vertex of ''Tranatocetus'' is X-shaped in dorsal view. However, ''Tranatocetus'' differs in having a wide skull with laterally expanded squamosals, straight ascending processes of maxillae which extend parallel to each other (rather than tapering and converging posteriorly), small lateral projection of the posterior meatal crest on the posterolateral side of the postglenoid process and paroccipital processes extending far posterior to the occipital condyles.

Classification

''Tranatocetus'' was originally classified as a member of the thalassothere family Tranatocetidae, which includes a number of mysticetes more closely related to Balaenopteroidea than to

Cetotheriidae Cetotheriidae is a family of baleen whales (parvorder Mysticeti). The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by recovered the living ...

. When first described, ''Tranatocetus'' was erected as a new species of ''Mesocetus'', ''M. argillarius''. However, a detailed redescription of this species found it to be generically distinct from ''Mesocetus'' proper, necessitating its recognition as a new genus. The phylogenetic analysis conducted by Marx ''et al.'' (2019) recovered ''Tranatocetus'' deeply nested within the family Cetotheriidae, as

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to ''

Metopocetus ''Metopocetus'' is an extinct genus of baleen whale belonging to the family Cetotheriidae. The type species is ''Metopocetus durinasus''. Description ''Metopocetus'' is diagnosable by lateral occipital crests continuous with temporal crests tha ...

''.

References

{{Taxonbar, from=Q22286638 Miocene cetaceans Prehistoric cetacean genera Miocene mammals of Europe