XV.—On the Occurrence of Functional Teeth in the Upper Jaw of the Sperm Whale

• Published in: Proceedings of the Royal Society of Edinburgh
• Main Authors: Ritchie, James, Edwards, A. J. H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1914
• Subjects: Sperm whale
• Online Access: http://dx.doi.org/10.1017/s0370164600031333; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0370164600031333

Writers on mammalian anatomy are united in stating that one of the characteristics of the Cetacean family Physeteridæ is the presence of functional teeth in the lower jaw only. Typical statements are those of Flower and Lydekker (1891): “No functional teeth in the upper jaw”; Beddard (1900): “Teeth found in both jaws, but those of lower jaw alone functional; often very reduced in number”; Turner (1912): “Functional teeth in lower, but not in upper jaw.” A possible exception is the Pigmy Whale, Kogia , in which the upper jaw may altogether lack teeth or may possess an anterior rudimentary pair (as in K. simus , Owen) the utility of which is a matter of some doubt.