THE STORY TOLD BY FOSSIL PLANTS 



may be seen; Permian is from the province of Perm, in Rus- 

 sia. Or the name may have been suggested by the character 

 of the rock, as Carboniferous, a term applied to the rocks of 

 the coal age. 



After this era of ancient Hfe, the Palaeozoic, came the 

 Mesozoic era, a time in which the forms were intermediate 

 between the old and the new. The Mesozoic era is divided 

 into three periods — the Triassic, the Jurassic, and the Cretace- 

 ous. The Triassic is so named because in that period three 

 principal kinds of rock formations were deposited in southern 

 Germany; the Jurassic is so named because the rocks of that 

 period are very conspicuous in the Jura Mountains; and the 

 Cretaceous gets its name from the fact that its characteristic 

 rock is chalk (creta in Latin). 



The Mesozoic era was followed by the Cenozoic, the time 

 of modern life. In the rocks of this era we find the remains 

 of warm-blooded animals and flowering plants, and in those 

 of the later part of the era we find the skeletons and flint 

 implements of ancient man. 



Many fossil seaweeds are scattered through the older 

 rocks, but the first land plants found in abundance as fos- 

 sils lived in middle Palaeozoic time (Devonian) . (See table 

 on page 160.) Some of these may be considered transi- 

 tional between seaweeds and true land plants (Fig, 2). 

 Others were synthetic forms combining features of organi- 

 zation which during subsequent ages became segregated 

 and characteristic of separate orders of plants. Such an 

 ancestral plant is Hyenia (Fig. 4) which combines fea- 

 tures of the later club mosses and horsetails. Others by 

 their complexity indicate a long period of terrestrial exist- 

 ence. Some of these Devonian plants are true seed ferns 

 (Figs. 3 and 4); others are arborescent club mosses, which 

 combine the features of plants of later Palaeozoic time 

 (Fig. 5). Another later Devonian type, widespread geo- 



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