Diunatans luctoretemergo

Diunatans luctoretemergo is an extinct rorqual and the type species of the genus Diunatans, a name that means long-distance swimmer. It lived in the North Sea during the Early Pliocene, and its two known specimens were collected from the Kattendijk Formation in the Dutch province of Zeeland, which is Zanclean in age. The species name comes from Luctor et Emergo, the motto of Zeeland, Latin for I struggle and I emerge. It was about the size of the living minke whale and has a skull with a large occipital condyle, very small nasal bones and a large tympanic bulla. It is considered a stem balaenopterid because it falls outside the clade of Balaenoptera and Megaptera that includes all living rorquals, and it is the only known fossil rorqual from the North Sea.