Historical Geology Understanding Our Planet\'s Past
Carboniferous coal deposits. Most reproduced with spores, but the extinct seed ferns bore seeds. The spermatophytes are the high ...
variety of branching patterns to expose them to as much sunlight as possible to maximize photosynthesis. Competition for light w ...
age” in the sense that little is known about the soft bodies of animals that inhabited the seas. Soft-bodied marine animals livi ...
noes. As the volcanoes subsided beneath the sea, the rate of coral growth matched the rate of volcanic subsidence.This kept the ...
A large variety of corals are well represented in the fossil record and resemble many of their modern counterparts. The tabulate ...
rapidly in the Silurian. Numerous species succumbed to extinction at the end of the period. The echinoderms with fivefold and bi ...
THE LAND INVASION The colonization of the continents is one of the most important steps in evo- lutionary history. Strangely, af ...
The first invertebrates to crawl out of the sea and populate the conti- nents were probably crustaceans.These ancient arthropods ...
LAURASIA During the Silurian, all northern continents collided to form Laurasia, which included the interior of North America, G ...
After the rapid continent building,the interior of Laurentia experi- enced extensive igneous activity from 1.6 to 1.3 billion ye ...
About 700 million years ago, Laurentia collided with another large con- tinent on its southern and eastern borders,creating a ne ...
Over the past half-billion years, about a dozen individual continental plates came together to form Eurasia. It is the youngest ...
When Laurentia united with Baltica, island arcs in a proto–Pacific Ocean called the Panthalassa began to collide with the wester ...
The continents were lowered by erosion. Shallow seas flooded inland, covering more than half the present land area. The weight o ...
flows, tillites, and coal beds, reaching a total thickness of 20,000 feet. Between layers of coal were fossil leaves of the exti ...
T his chapter examines life in the sea and the first vertebrates to come onto the land during the Devonian period. The Devonian, ...
many tropical marine animals, paving the way for entirely new species espe- cially adapted to the cold. THE AGE OF FISH The Devo ...
selected for survival, which is why certain species survive one major extinc- tion after another. This is particularly true for ...
The evolution of jaws also improved fish respiration by supporting the gills.After a fish draws water into its mouth, it squeeze ...
rear appendage on the opposite side. Such an adaptation would have eased the transition from sea to land, making the coelacanth ...
«
2
3
4
5
6
7
8
9
10
11
»
Free download pdf