TRANSITION FROM THE PALAEOZOIC TO THE MESOZOIC. 409 



hollows, instead of sea-urchins and star-fishes and crabs, he would have 

 found crinoids and trilobites. In the open sea he would have found as 

 rulers, instead of whales and sharks and teleosts and cuttle-fish, huge 

 cuirassed Sauroids and the straight-chambered Orthoceras. Turning 

 to the land, he would have seen at first only desolation ; for there were 

 almost no land-plants until the Devonian, and almost no land-animals 

 until the Coal. During the Coal there were extensive marshes, over- 

 grown with great trees of Sigillaria, Lepidodendron, and Calamites, 

 with dense underbrush of Ferns, inhabited by insects and amphibians ; 

 no umbrageous trees, no fragrant flowers or luscious fruits, no birds, no 

 mammals. These " dim, watery woodlands " are flowerless, fruitless, 

 songless, voiceless, except the occasional chirp of the grasshopper. If 

 the observer were a naturalist, he would notice, also, the complete absence 

 of modern types of plants and animals — it would be like another world. 

 This long dynasty was overthrown, this reign of Fishes and Amphib- 

 ians ended, the physical conditions described above were changed, and 

 the whole fauna and flora destroyed or transmuted by the Appalachian 

 revolution. At the end of the Palaeozoic, the sediments which had been 

 so long accumulating in the Appalachian region at last yielded to the 

 slowly-increasing horizontal pressure, and were mashed and folded and 

 thickened up into the Appalachian chain, and the rocks metamorphosed. 

 In America, this chain is the monument of the greatest revolution 

 which has taken place in the earth's history. At the same time great 

 changes took place in the West also. The Utah basin region was up- 

 heaved to form land, the Nevada basin region sank and became sea- 

 bottom, and the Pacific shore-line was transferred eastward to the 117th 

 meridian about Battle Mountain. In other words, the Basin region 

 Palaeozoic continent was transferred eastward its own breadth to form 

 the Basin region Mesozoic continent (King). Similar and very exten- 

 sive changes in physical geography must have taken place in other por- 

 tions of the globe, otherwise we can not account for the enormous 

 changes in physical conditions and fauna and flora. Many of these have 

 been traced, but we can not yet trace them as clearly as in America. 



Transition from the Palaeozoic to the Mesozoic — Permian Period. 



The Permian a Transition Period. — The Palaeozoic era was closed 

 and the Mesozoic inaugurated by the Appalachian revolution. All the 

 great revolutions in the earth's history are periods of oscillations. Such 

 oscillations produce unconformity. They also produce changes of cli- 

 mate, and therefore of fauna and flora. We find, therefore, that the 

 Mesozoic rocks are universally, or nearly universally,* unconformable 



* In the Rocky Mountain region there seems to be complete conformity in some 

 places. (King, Fortieth Parallel Survey, vol. i, p. 266.) 



