. Outlines of zoology. Zoology. 7o8 MAMMALIA. Some Eocene fossils, known as Zeuglodonts, are regarded by some (Lydekker, Dames) as primitive Cetaceans— Archaeoceti—less specialised than modern forms, but Prof. D'Arcy Thompson has advanced strong arguments in favour of their affinities vfith Pinniped Carnivores. In regard to the possible affinities of the Cetacea, Sir Wm. Flower maintains (i) that the hypothesis of their descent from Ichthyopterygian reptiles is untenable, (2) that they are separated from an alliance with Carnivora by. Fig. 261.—Vertebra, rib, and sternum of Balo^noptera, (From
. Outlines of zoology. Zoology. 7o8 MAMMALIA. Some Eocene fossils, known as Zeuglodonts, are regarded by some (Lydekker, Dames) as primitive Cetaceans— Archaeoceti—less specialised than modern forms, but Prof. D'Arcy Thompson has advanced strong arguments in favour of their affinities vfith Pinniped Carnivores. In regard to the possible affinities of the Cetacea, Sir Wm. Flower maintains (i) that the hypothesis of their descent from Ichthyopterygian reptiles is untenable, (2) that they are separated from an alliance with Carnivora by. Fig. 261.—Vertebra, rib, and sternum of Balo^noptera, (From specimen in Anatomical Museum, Edinburgh.) C""., Centrum ; , neural arch ; ^.. neural spine ; trans\erse process ; A"., rib ; St., sternum. many essential characters, (3) that they exhibit several, though by no means close, affinities with Ungulata. The same authority refers to several facts which suggest that, in their transition from terrestrial to marine life, the Cetaceans may have passed through a stage in which they lived in fresh water. [ 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 Thomson, J. Arthur (John Arthur), 1861-1933; Newbigin, Marion I. (Marion Isabel), 1869-1934; Smith, Preserved, 1880-1941. fmo. New York, D. Appleton & Co.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
