New records of the Gulf-Stream beaked whale, Mesoplodon gervaisi, and some taxonomic considerations. American Museum novitates ; no. 1993

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New York, N.Y. : American Museum of Natural History
"An apparently adult male of Mesoplodon gervaisi stranded on the Gulf coast of Florida at Boca Grande, about latitude 26° 42' N., in April, 1959, and most of its skeleton was recovered and presented to the American Museum of Natural History. Its protruding mandibular teeth were said to fit into grooves in the skin of the upper jaw. It is the second adult male recognized and the twelfth known specimen of the species. The left tooth of a male beaked whale stranded at Padre Island, Texas, about latitude 27° 15' N., in September, 1946, is now identifiable as Mesoplodon gervaisi and is the thirteenth specimen made known as such. An apparently adult female of this species stranded on the Atlantic coast of Florida near Vero Beach at about latitude 27° 45' N., about February of 1958, and its skeleton was secured by the United States National Museum. Its skull is the largest on record for the species, and it is the fourteenth known specimen. From study of these materials, the skulls of three other specimens of gervaisi, and photographs of five others, it has been possible to reject finally a number of propositions that have been made in the literature from studies of smaller amounts of material of this and related species, and to offer the following findings: 1. The discovery by Flower (1878) that the relative position of the maxillary and premaxillary foramina separates certain species of Mesoplodon from others was made when only one specimen of gervaisi was known and before mirus had been found. Even as altered by Nishiwaki and Kamiya (1958), it does not satisfactorily distinguish either gervaisi or mirus. 2. The partial skull from North Long Branch, New Jersey (Allen, 1909), is shown here to belong to gervaisi. 3. Mesoplodon pacificus Longman is shown to differ from M. mirus in too many skull characters to be considered a subspecies of it. 4. To the sexual dimorphism in gervaisi previously restricted to the single pair of mandibular teeth, one may now add that relatively greater length of the symphysis seems to characterize adult females, and that greater size of the skull (and presumably the size of the whole animal) may also characterize the female. 5. The known maximum length of gervaisi is concluded to be 467 cm. (15.3 feet). 6. The length of the mandible seems to provide an indication of relative age. 7. It appears that the mesirostral canal of gervaisi may fill more slowly in females than in males. 8. The three new locality records for gervaisi support the concept that gervaisi may have a somewhat more southern range than that of mirus"--P. 32-33.
35 p. : ill. ; 24 cm.
Includes bibliographical references (p. 33-35).