An encyclopedic and vividly illustrated reference.
Gone but never forgotten -- no other life form has captured our imagination and attention like dinosaurs. Dinosaurus is organized into the major dinosaur families and identifies 500 species -- creature by creature, from the voracious flesh-eaters to the egg-stealers to the vegetarians. What they looked like. What they ate. How they fought, lived, and died. A dramatic full-color illustration of each dinosaur is accompanied by a concise explanation of their traits and habits.
At-a-glance Fact Files describe:
Dinosaurus challenges and discredits popular myths and long-standing legends. For example: the dinosaur known as Brontosaurus never even existed in the first place. Was Tyrannosaurus really the biggest meat-eater of all time? Were flying dinosaurs simply feeble gliders? Could sea dinosaurs out-swim today's fastest fish?
Brimming with the latest research, from contemporary digs in North America, Mongolia, Europe and China, Dinosaurus is comprehensive, innovative, and as compelling and exciting as the dinosaurs themselves.
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Steve Parker is a Scientific Fellow of the Zoological Society and is author of The Encyclopedia of Sharks.Excerpt. © Reprinted by permission. All rights reserved.:
Excerpted from the
When dealing with dinosaurs, there is perhaps only one certainty: the "facts" will change. Of course, the lives of the dinosaurs and other prehistoric animals in this book cannot be altered. That world is long gone. What does change is our interpretation of how dinosaurs lived and died. Almost every week, new discoveries are announced. Debates and disagreements occur, old ideas are revived, and new ideas are challenged. Perhaps once a year, a fresh fossil find or a new theory of prehistory catches the public imagination. These newsworthy events tend to focus on which was the biggest or the fiercest of dinosaurs, which came first, and how their extinction is explained. It is the progress in our knowledge of these ancient animals that makes their study so exciting and enduring.
Dinosaurs in Perspective
A number of kinds, or species, of animals, plants and other living things in existence today likely exceeds 10 million. Insects are the vast majority. Some of the other main groups of invertebrates (animals without backbones) include around 100,000 species of slugs, snails, octopuses, mussels and other molluscs; 40,000 species of crabs, prawns, lobsters and other crustaceans; and 10,000 species of the simplest of all animals, sponges. Prehistoric versions of all these groups are shown in this book. Among the vertebrates, fish are by far the most species rich group, at 25,000, followed by some 9,000 species of birds, 7,000 reptile species and 5,000 types of amphibians. Our own group, the mammals, trails behind, with around 4,500 species. Overall, close to two million living species from all groups, including plants, have been described, named, and catalogued by scientists. Yet more than 99 out of every 100 kinds of living things that have ever existed are no longer around. They form a vast array of life forms that have appeared and then disappeared on our planet.
Within this array, scientists have listed several hundred types of dinosaurs. Each of these is a genus (plural, genera) containing one or more very closely related species. For example, Tyrannosaurus, "tyrant reptile," is a genus of huge meat-eaters from very late in the dinosaur age, about 70-65 million years ago. The best-known species is Tyrannosaurus rex, "king tyrant reptile." The differences between dinosaur species within the same genus are often complex and are much debated, depending on interpretation of tiny details on the fossils. This book describes principally genera of dinosaurs and other prehistoric creatures, with a few excursions to the level of species to illustrate certain points.
The classification of some 400 genera of dinosaurs, and of several species within many of these genera, is a terrific achievement in relation to a group of animals known only from fossils. The fossil record is very scarce, patchy and fragmentary. The chances are that it shows us only a few kinds of dinosaurs that existed. The numbers and varieties of dinosaurs we do know about give some idea of the dominance they achieved over other forms of land life. Their fossils accumulated over a span of more than 160 million years.
In one sense, "evolution" simply means change. Living things have changed since they began, as shown by evidence from the fossil record. Types of plants and creatures appeared, flourished for a time, and then faded away. The bird called the passenger pigeon teemed in the millions in North America before European settlers arrived, but was slaughtered into oblivion by the early 20th century. The dodo, the quagga (a hoofed animal resembling a horses or zebra) and aurochs (ancestor of today's cattle) all died out within the past millennium. And all of these recent changes have been due to "unnatural" interference by humans in the natural world. But all through Earth's history, such disappearances, or extinctions have occurred on a regular basis. There is a turnover of species today, as there has been since life began.
Farther back in time, during the Age of Dinosaurs, the same changes occurred. They were due to the pressures of living -- finding food, escaping predators, sheltering from the elements, competing for a breeding partner and generally struggling to survive. If every offspring of every living thing survived, the world would soon have become impossibly crowded. No animal had a life free from hardships or interference. Natural forces or pressures, such as trying to get food or avoid a hunter, meant that some living things died out. The survivors were, in effect, those left after selection by nature's pressures -- which is what scientists mean by "natural selection."
What determined whether a living thing survived the struggle for existence? In part, the genetic "instructions," in the form of the chemical DNA, for bodily features or characteristics. Genes are inherited from parents. The way that reproduction works means that genes sometimes undergo change (mutation) or come together in different combinations (recombination) in different individuals. These are regular occurrences, and the result is that offspring vary from their parents and from each other. These variations may be small, but can be enough to tip the balance in the trial of survival. Useful features or characteristics mean that an individual is more likely to survive and breed, passing on its genes to its offspring by the process of inheritance.
Through prehistory, dinosaurs and other living things were subjected to the pressures of natural selection. If the environment had remained constant for all this time, then perhaps the dinosaurs, and life in general, would have reached a steady state of equilibrium. Conditions, however, have always changed. Climates have fluctuated, temperatures have varied, sea levels have gone up and down. Living things responded to the alterations by evolving. As they did so, living things were also part of the environment in relation to each other, causing further changes to evolve. Sometimes, evolution happened slowly and gradually, over millions of years. At other times, it occurred relatively quickly, followed by a long period of relative stability, which is known as "punctuated equilibrium" -- evolution by "jumps."
Evolutionary history is sometimes imagined as a "tree of life." There were one or two types of life early on, gradually giving rise to more and more different kinds, and so on. The end points or "twig-tips" are animals and plants alive today. However and untidy "hedge of life" might be more apt, since some species died out as others arose. Apart from life's earliest stages, there has always appeared to be great diversity and abundance.
The principal evidence for the existence of dinosaurs and other long-gone living things comes from fossils. These are the remains of organisms, or the traces they left, which have been preserved, usually in the form of rock. The phrase "bone to stone" sums up how a fossil forms, although not only bones have been preserved, and not all fossils are in the form of stony minerals. Also, the process of fossilization is long and beset by chance events. The fossil record in the rocks, and the story it tells of life on Earth, should therefore be approached with caution.
An old dinosaur lies down on a riverbank and dies. Then the river floods and, as the water subsides they leave a thick layer of sandy sediment that covers the animal's body. The fleshy parts of the dinosaur, such as its muscles and guts, rot away slowly. The harder parts, such as the bones, teeth, claws, and horns, are more resistant to decay. Through time, the sand is buried deeper as more layers accumulate on top. The pressure and temperature of the layers rise with increasing depth. The originally loose sand is gradually compressed and cemented by rock minerals, to become hard sands
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Descripción Firefly Books, 2003. Hardcover. Estado de conservación: New. Never used!. Nº de ref. de la librería P111552977722
Descripción Firefly Books. Hardcover. Estado de conservación: New. 1552977722 New Condition. Nº de ref. de la librería NEW7.0635485