Eocene cetaceans from the Belgian-Dutch coastal waters

Thirteen cetacean vertebrae and a vertebral neural arch fragment are described and figured. All have been dredged from the southern part of the North Sea, in the tidal channels Het Scheur, Belgium, and Wielingen in the estuary of the Westerschelde, near the Belgian-Dutch border. Here, strata of the Middle Eocene Maldegem Formation and of the Late Eocene parts of the Zelzate Formation crop out at the seafloor. The vertebral centra are mostly large and show basilosaurid characteristics. Based upon morphology, three different main types are recognised. The first morphotype apparently represents a new taxon, the second one closely resembles a vertebra of a cetacean from the Priabonian of Maastricht, the Netherlands and the third is assigned to the genus Pachycetus which taxon is, amongst others, also known from the Bartonian and maybe Priabonian of Ukraine and Germany in Europe. In the vertebrae of the latter morphotype, maybe two subtypes, a large and a smaller one can be discerned. With at least three different large taxa, the seafloor at Wielingen and Het Scheur appears to be a surprisingly important site of Eocene cetacean remains in Europe.