The vegetation, however, particularly in the Upper Cretaceous, begins to assume a more modern aspect and we find along with the ancient types of ferns (Cladophlebis, Thyrsopteris), broad-leaved conifers (Nageiopsis), and juniper-like evergreens (Moriconia), numerous leaves of oaks, willows, figs, magnolias, sassafras and laurel. The earliest known palms are found at this time. The Cretaceous clays which skirt Raritan Bay in New Jersey abound with these layers of leaves, as do also the Dakota sandstones of the middle west. The magnificent specimen of sequoia with the large cone and the needle-like curved leaves shown in Fig. 2 is from the clays near Cliffwood, N. J., where the twigs are among the most abundant fossils, looking like elegant lithographs against the background of dove-colored clay. This species had cones almost exactly like those of the living Californian tree and the foliage was also very similar. It was a very wide ranging form, and is considered to have been the source (in part at least) of the amber which is so common in the coastal plain Cretaceous at certain points.
Fig. 3 shows a flat-leaved form and attached cone of a species more like the modern redwood, in fact it was probably one of its ancestors, which first appeared during the Cretaceous and which became widely distributed, and continued through the Miocene. During the three to five million years of Cretaceous time the sequoias flourished and became widespread. They saw many changes going on all about them. Beneath their shade new races were springing up; the plants of a modern type which were to replace all others in the struggle for existence had obtained their start; animals gamboled about their trunks or climbed in their branches[1] that were destined to replace the unintelligent and clumsy reptiles, and by and by to give rise to the horses, dogs and cats of a later day, and finally to produce that animal which was to attain universal distribution, and to be the destructor of countless other species—man.
Remains of sequoias from the lower beds of the Cretaceous have been found in western Europe, in Spitzbergen, in Texas and in the eastern United States. In slightly more recent deposits we find them in Greenland, Canada, in the Black Hills and in Montana. By the middle of the Cretaceous we find over a dozen different species spread over the United States, with still others in Greenland and in central and western Europe. Their remains are often extremely common, whole branches bearing numerous cones, and innumerable twigs, often beautifully preserved, being common fossils. The warm humid climate of the period seems to have been very favorable for their development, and the elevation of the land, by which natural bridges, such as those
- ↑ The Cretaceous mammals are all small, about the size of squirrels, and were probably arboreal forest dwellers.
