. Bulletin of the Department of Geology. Geology. 1914] Taylor: Aquatic Adaptation in the Carnivora 483 the tail is used as a rudder. The shape of the tail and the presence of the so-called flanges upon it laterally have led to the suggestion by Lull3' that they are homologous to the ex- panded flukes on the tails of certain of the Cetacea and Sirenia. the posterior position of the flukes in these groups being a mech- anical adaptation which has been accelerated in its appearance so as to be embryonic. Vertebrae General Characters.—The form of the vertebrae in the sea- otter is different from
. Bulletin of the Department of Geology. Geology. 1914] Taylor: Aquatic Adaptation in the Carnivora 483 the tail is used as a rudder. The shape of the tail and the presence of the so-called flanges upon it laterally have led to the suggestion by Lull3' that they are homologous to the ex- panded flukes on the tails of certain of the Cetacea and Sirenia. the posterior position of the flukes in these groups being a mech- anical adaptation which has been accelerated in its appearance so as to be embryonic. Vertebrae General Characters.—The form of the vertebrae in the sea- otter is different from that in the river otter, in that the inter- vertebral foramina are larger, especially posteriorly, the zyga-. Figs. 7-9. Lateral views of selected vertebrae of river otter, sea- otter, and seal. x%. Figs, 7a, lb and 7c. Vertebrae of river otter (Lutra canadensis). Fig. la, fifth cervical; lb, third lumbar; 7c, fourth caudal. Figs. 8a, 86 and 8c. Vertebrae of sea-otter (Latax lutris nereis). Fig. 8a, fifth cervical; 8b, third lumbar; 8c, fourth caudal. Figs. 9a, 9b and 9c. Vertebrae of seal (Phoca vitulina). Fig. 9a, fifth cervical; 9b, third lumbar; 9c, fourth caudal. 35 Lull, B. S., '' Eelation of embryology and vertebrate paleontology,'' Popular Science Monthly, vol. 77 (1910), p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original University of California, Berkeley. Dept. of Geology. Berkeley : The University Press
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