Historical Geology Understanding Our Planet\'s Past
valleys (Fig. 125).The existence of sedimentary layers beneath the core of the Appalachians suggests that thrusting involving ba ...
folded rocks, formed when two plates came together into the continent of Antarctica. Prior to the end of the Permian, the younge ...
gases, thereby significantly lowering surface temperatures. As the continents rose higher, the ocean basins dropped lower.The ch ...
conditions, reef building intensified, forming thick deposits of limestone that were laid down by prolific, lime-secreting organ ...
species was restricted to narrow areas around the tropics. Species trapped in confined waterways that were unable to move to war ...
rebound after a mass extinction than their more sensitive neighbors. Never- theless, both groups declined considerably. However, ...
On land, some 70 percent of the amphibian families and about 80 percent of the reptilian families also disappeared. Even the ins ...
Paleozoic.It also explains why the reptiles, which adapt readily to hot, dry cli- mates, replaced the amphibians as the dominant ...
the world practically devoid of species, thereby paving the way for the ascen- sion of entirely new life-forms. In the aftermath ...
T his chapter examines the evolution of the dinosaurs and of the continents during the Tr iassic period.The Triassic, from 250 t ...
on their way to their present-day locations. The breakup of Pangaea created three new bodies of water, including the Atlantic, A ...
ing reptiles, mammals, and perhaps the predecessors of birds. (The true birds did not appear in the fossil record for another 50 ...
on dry land. They successfully inhabited desert areas in the interiors of conti- nents and other desolate places where they coul ...
a missing chapter in insect evolution in an extraordinarily rich fossil quarry in southern Virginia, near the North Carolina bor ...
evolution, the animals had to compete with huge crocodiles, flying reptiles called pterodactyls, and other fierce reptiles. In t ...
The success of the dinosaurs is exemplified by their extensive range.They occupied a wide variety of habitats and dominated all ...
living today.They were very common and ranged over wide spaces like mod- ern-day sheep.The smallest known dinosaur footprints ar ...
relatives of dinosaurs.The skeletons of many small dinosaurs resemble those of birds (Fig. 136). Many large bipedaled dinosaurs ...
had relatively large brains and were fairly intelligent (Fig. 137), able to react to a variety of environmental pressures. The v ...
Free ebooks ==> http://www.Ebook777.com per away from danger the way modern crocodile young do. However, a fossil discovery o ...
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