(FIGURE 224. Zeuglodon cetoides, Owen. Basilosaurus, Harlan.
Molar tooth, natural size.)
(FIGURE 225. Zeuglodon cetoides, Owen. Basilosaurus, Harlan.
Vertebra, reduced.)
Professor Owen first pointed out that this huge animal was not reptilian, since
each tooth was furnished with double roots (Figure 224), implanted in
corresponding double sockets; and his opinion of the cetacean nature of the
fossil was afterwards confirmed by Dr. Wyman and Dr. R.W. Gibbes. That it was an
extinct mammal of the whale tribe has since been placed beyond all doubt by
discovery of the entire skull of another fossil species of the same family,
having the double occipital condyles only met with in mammals, and the
convoluted tympanic bones which are characteristic of cetaceans.
CHAPTER XVII.
UPPER CRETACEOUS GROUP.
Lapse of Time between Cretaceous and Eocene Periods.
Table of successive Cretaceous Formations.
Maestricht Beds.
Pisolitic Limestone of France.
Chalk of Faxoe.
Geographical Extent and Origin of the White Chalk.
Chalky Matter now forming in the Bed of the Atlantic.
Marked Difference between the Cretaceous and existing Fauna.
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