THE CRETACEOUS PERIOD, 173 



The vegetation.-— At the opening of the (Upper) Cretaceous in America, 

 the angiosperms were in marked dominance, and during the period genera 

 now living became more and more abundant, giving to the whole a dis- 

 tinctly modern aspect. Extinct forms came to occupy a subordinate 

 place. Among these were Zamites, Podozamites, and Baiera, which 

 were common in the previous periods, but disappeared at the close 

 of the Cretaceous. Among the living genera that made their appear- 

 ance were Podocarpus, the dominant pine of the southern hemisphere, 

 Betula (birch, Fig. 408, g), Fagus (beech), Quercus (oak, Fig. 408, e), 

 Juglans (walnut), Myrica (tamarisk, mayberry, Fig. 408, b), Ario- 

 carpus (bread-fruit tree), Platanus (plane-tree), Liriodendron (tulip- 

 tree, Fig. 408, a), Per sea (laurel), Cinnamomum (cinnamon), Acer 

 (maple), Ilex (holly), Liquidamber (sweet-gum), Hedera (ivy), Cornus 

 (cornel), Nerium (oleander), and Viburnum (wayfaring-tree, arrow- 

 wood, Fig. 408, /). Prominent among those that had come over from 

 the Lower Cretaceous were Ficas (Fig. 408, i), Sassafras (Fig. 408, /i), 

 Magnolia (Fig. 408, c), and Sterculia (flame-tree, Fig. 408, d). Among 

 the gymnosperms, there was a notable development of the sequoias, 

 which now embrace the giant trees of California, and there were 

 advances among other conifers. The modern genus Cycas was present, 

 and the ginkgo had some prominence, though never a leading type. 

 Worthy of special note was the presence of genera in Europe and the 

 United States which are now confined to the southern hemisphere, 

 as Eucalyptus and the pine above mentioned. Some of these remained 

 in the northern regions into the early Cenozoic. 



Previous to this period, and in its earlier stages, monocotyledons 

 played but an insignificant part in the floral record, but they now 

 began to assume importance. Many palms were present before the 

 close of the period, some of which at least were closely allied to existing 

 forms. Their presence in northern latitudes implies a mild climate. 

 Of even more interest, because of their relations to the evolution of 

 grazing animals, was the appearance of grasses, which do not, how- 

 ever, appear to have attained prominence thus early. It is worthy of 

 remark here that the Cretaceous revolution in vegetation was not 

 only great as a phytological event, but was at least susceptible of 

 profound influence on zoological evolution, for it brought in new and 

 richer supplies of food in the form of seeds, fruits, and fodder. At 

 present, neither the ferns, equiseta, cycads, nor conifers furnish food 



