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The manus of the Narwhal, Monodon monoceros L.
Author(s) -
Eales N. B.
Publication year - 1954
Publication title -
proceedings of the zoological society of london
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0370-2774
DOI - 10.1111/j.1469-7998.1954.tb07777.x
Subject(s) - biology , manus , anatomy , phalanx , zoology
S ummary1 The flipper of the Narwhal has been investigated in foetal and adult stages, with special reference to the carpus. 2 In the foetus, radiale, intermedium and ulnare, a single centrale, trapezoid, magnum and separate distal carpals 4 and 5 are present. There is no trace of a pisiform or of a trapezium. The centrale fuses with the intermedium. Distal carpals 4 and 5 unite to form an uneiform. In the adult there are three bones in the distal row. 3 In the allied Delphinapterus (adult) the form of the flipper is similar, but the trapezoid is missing, as it is in Phocaena (Phocaenidae). 4 In the Delphinidae, as illustrated by Globiocephala , trapezoid, magnum and uneiform are present. 5 In broad‐handed whales (Monodon, Delphinapterus, Phocaena) the number of phalanges decreases with age, in narrow‐handed whales this number increases as the whale matures. 6 The carpus of whales is of the interlocking type. 7 A centrale has now been found during development in all mammals except some ungulates. 8 Whales are the only mammals retaining traces of separate fourth and fifth distal carpals.