Page:Popular Science Monthly Volume 67.djvu/475

Rh by earthquakes eight million years ago as are the inhabitants of New Jersey at the present time by the sinking of their eastern coast. Events moved with inconceivable slowness then as now, though, of course, progress was quickened now and then. Our Jurassic sojourner would find everything strange. In the marshes flourished great ferns with undivided evergreen fronds (Marattiaceæ), and numerous representatives of our modern royal and cinnamon ferns (Osmundaceæ). Close by, ancient tree-ferns (Cyatheaceæ) vied with an amazing variety of forms known as cycads—curious plants of which the commonly cultivated sago palm is a familiar example. In the dryer spots flourished the numerous ancestors of the ginkgo, the maiden-hair tree, that curious relic of bygone days, which has been saved from extinction in modern times by the loving care of the priests about the temples of China and Japan.

The only representatives of those flowering plants which are dominant in the vegetation of the world to-day, the Angiosperms. were the little-known and curious (probably) semi-aquatic plants with netted veined leaves, which have been named pro-angiosperms. Ancient lungfishes, gar pikes and crocodiles haunt the rivers; out at sea are swarms of sharks and ganoid fishes. Bat-like flying reptiles are the common denizens of the air, the primitive toothed birds with long reptilian tails being in the minority. Sea-inhabiting reptiles of gigantic size, long-necked plesiosaurs and dolphin-like ichthyosaurs, land-inhabiting dinosaurs (the name means terrible lizard), of immense size and bizarre form, are the dominant creatures, while the noble class of mammals with man at their summit is still but a promise and, so far as the fossils indicate, represented by only a few forms of mouse-like size. The continents had not yet assumed their modern dimensions. Such great mountain chains as the Alps. Himalayas and Rockies had not been elevated; and yet the sequoia flourished and its cones were not very different from those found in California at the present time.

The next succeeding geological period, the Cretaceous, continued to be the age of gigantic reptiles, some of which are shown in Fig. 4. The two left-hand monsters figured were between twenty and forty feet long, and were ancient Jerseyites, the spoonbill, a herbivorous, and the leaper, a carnivorous, species. Occasional bones and teeth of these and other related creatures are found in the marl beds that were deposited in the sea off the eastern coast of those days. The Mississippi valley was part of a great gulf that extended northward from the present Gulf of Mexico almost to the Arctic circle, and was a veritable summer sea, peopled with gigantic sea-lizards (mosasaurs), and with a host of other strange forms. Flying reptiles with a spread of fifteen to twenty feet circled overhead.