EUGENE M. MCCARTHY, PHD GENETICS
Delphinapterus leucas [Beluga]
× Tursiops truncatus [Common Bottle-nosed Dolphin] NHR?? Post (2001) suggests an aberrant fossil atlas (Late Pleistocene-Early Holocene) from the North Sea might be the result of a “liaison between a white whale (Delphinapterus leucas) and a bottle-nose dolphin (Tursiops truncatus).” T. truncatus is assigned to family Delphinidae, so this is an interfamilial cross.
× Monodon monoceros [Narwhal] NHR? CON: Arctic Ocean. Heide-Jørgensen and Reeves (1993) describe and discuss the skull of a probable hybrid from Disko Bay, West Greenland (68˚50´N, 53˚10´W). It was shot offshore in mid-May of 1986 or 1987 by an Inuit hunter who kept only its skull. Though the skull is larger than those of normal narwhals and belugas, Heide-Jørgensen and Reeves assert (p. 258) that “the intermediate characteristics of the skull and dentition are consistent with the hypothesis that the anomalous whale was a narwhal-beluga hybrid.” (So its large size would be due to heterosis.) They go on to say that, according to the hunter, “the intact animal looked like a combination of narwhal and beluga, with the tail of a narwhal and pectoral flippers resembling those of a beluga.” Most conceptions for both beluga and narwhal occur in April-May, a season when both are abundant off West Greenland. The specimen is in the Greenland Fisheries Research Institute, Copenhagen (no. 361), so genetic testing of the specimen would be possible. The various supposed pictures seen around the Internet showing this hybrid as a living are apparently all fakes since the only known specimen is a skull. Kelly et al. 2010.
Monodon monoceros [Narwhal] See: Delphinapterus leucas.
By the same author: Handbook of Avian Hybrids of the World, Oxford University Press (2006).
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On the Origins of New Forms of Life
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Georges Cuvier: A Biography
Prothero: A Rebuttal
Branches of Biology