Page:Popular Science Monthly Volume 53.djvu/223

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N the latter part of the Mesozoic age there was a great inland ocean, spreading over a large part of the present continent. The lands then above water were covered with a flora peculiar to the times and were inhabited by some of the animals which later distinguished the Cenozoic age. In the seas were reptiles, fishes, and turtles of gigantic proportions, armed for offense or defense. There were also oysterlike bivalves, with enormous shells, three or four feet in diameter, the meat of which would have fed many people. In time, this great ocean, swarming with Adgorous life, disappeared. Mountain ranges and plains gradually arose, casting forth the waters and leaving the monsters to die and bleach in Tertiary suns. As the waters remaining divided into smaller tracts, they gradually lost their saline stability. The stronger monsters gorged on the weaker tribes, until they, too, stranded on rising sand bars, or lost vitality and perished as the waters freshened. In imagination, we can picture the strongest, bereft of their food supply at last, and floundering in the shallow pools until all remaining mired or starved. It would be interesting to know how much of the great Cretaceous ocean forms a part, if any, of the vast oceans of to-day. If any part so survived, what became of the saurians carried forth into new ocean areas? Were they beaten on jagged rocks by powerful currents and destroyed, or did some of them escape only to perish in after ages? Water, as a rule, seeks its level; sometimes it is evaporated. If the Cretaceous ocean merely drained off into other areas before rising lands, it is perhaps not unreasonable to suppose that the descendants of some of the saurians might have survived in the Atlantic or Pacific as they had existed in the Mesozoic age. We can therefore only assume that the Cretaceous seas evaporated or gradually freshened until all the life they contained became extinct.

During the past twenty-five years explorers have collected tons of skeletons of the stranded sea serpents, or better, perhaps, serpentlike sea saurians. A sensational world has ever been on the lookout for sea serpents. It is possible that such tendencies are inherited from a very remote ancestor, a primeval, manlike animal, whose curiosity was aroused by glimpses of some surviving pythonomorph.

Almost everywhere on the expanse of the Cretaceous ocean might have been seen the snakelike forms of the elasmosaurs, the heads arrow-shaped, upheld by swanlike necks, rising from ten to twenty feet above the surface and scanning the sea or air for prey or enemies. The prey located below, they dived; the enemy seen