Balaenoptera cephalus

Balaenoptera cephalus is an extinct rorqual of the genus Balaenoptera, known from fossils found in the Calvert Formation of Maryland in the United States. It was originally thought to be a species of Eschrichtius, the gray whales, or of Cetotherium, but more recent analysis shows it to be a member of Balaenoptera. It is one of the valid fossil species of its genus listed in the English Wikipedia article on Balaenoptera, which treats several other named fossil species as doubtful because their remains are fragmentary or had no holotype specimen named. The Paleobiology Database records it as an extinct marine suspension feeder of the Serravallian age of the Miocene.