A monodontid cetacean from the Early Pliocene of the North Sea
Lambert, O.; Gigase, P. (2007). A monodontid cetacean from the Early Pliocene of the North Sea. Bull. Kon. Belg. Inst. Natuurwet. Aardwet. = Bull. - Inst. r. sci. nat. Belg., Sci. Terre 77: 197-210 In: Bulletin van het Koninklijk Belgisch Instituut voor Natuurwetenschappen. Aardwetenschappen = Bulletin de l'Institut Royal des Sciences Naturelles de Belgique. Sciences de la Terre. KBIN: Brussel. ISSN 0374-6291, more | |
Keywords | Geological time > Phanerozoic > Geological time > Cenozoic > Tertiary > Cenozoic > Neogene > Pliocene Mammalia [WoRMS]; Beluga Rafinesque, 1815 [WoRMS]; Monodon monoceros Linnaeus, 1758 [WoRMS]; Monodontidae Gray, 1821 [WoRMS] Belgium, Antwerpen [Marine Regions]; Belgium, Beveren [Marine Regions] Marine/Coastal | Author keywords | beluga, narwhal, Monodontidae, Pliocene, North Sea, palaeobiogeography |
Authors | | Top | - Lambert, O., more
- Gigase, P.
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Abstract | A partial skeleton from the Early Pliocene of Antwerp (north of Belgium), including a fragmentary skull, corresponds to the first record of a fossil member of the family Monodontidae in the North Sea. The vertex of the skull is lower than in the oldest known Monodontidae, the latest Miocene Denebola brachycephala, and the orbit is more anteriorly shifted. It differs from the two extant species of the family, the beluga Delphinapterus leucas and the narwhal Monodon monoceros, among others, in a shorter orbit and a shorter and wider antorbital notch. The anterior part of the temporal fossa is more elevated than in D. leucas and the rostrum lacked the modified pair of maxillary teeth of M. monoceros. Grooves observed at the surface of the skull bones are identified as shark teeth marks, either the result of a predation event or of scavenging. Several isolated ear bones from the Neogene of Antwerp are similarly referred to Monodontidae. The new specimens described here imply that members of the family migrated towards colder water before or during earliest Pliocene, well before the first Pleistocene records of Delphinapterus leucas in the North Sea. The palaeobiogeography of fossil Delphinidae, Monodontidae and Phocoenidae further suggests a Pacific origin for the crown- Delphinoidea of the North Atlantic realm. |
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