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Palaeontological deductions from the fossil remnants of extinct dinosaurs tell us much about their classification into species as well as about their physiological and behavioural characteristics. Geological evidence indicates that dinosaurs became extinct at the boundary between the Cretaceous and Paleogene eras, about 66 million years ago, at a time when there was worldwide environmental change resulting from the impact of a large celestial object with the Earth and/or from vast volcanic eruptions. However, apart from the presumption that climate change and interference with food supply contributed to their extinction, no biological mechanism has been suggested to explain why such a diverse range of terrestrial vertebrates ceased to exist. One of perhaps several contributing mechanisms comes by extrapolating from the physiology of the avian descendants of dinosaurs. This raises the possibility that cholecalciferol (vitamin D 3 ) deficiency of developing embryos in dinosaur eggs could have caused their death before hatching, thus extinguishing the entire family of dinosaurs through failure to reproduce.

Donald R. Prothero's science books combine leading research with first-person narratives of discovery, injecting warmth and familiarity into a profession that has much to offer nonspecialists. Bringing his trademark style and wit to an increasingly relevant subject of concern, Prothero links the climate changes that have occurred over the past 200 million years to their effects on plants and animals. In particular, he contrasts the extinctions that ended the Cretaceous period, which wiped out the dinosaurs, with those of the later Eocene and Oligocene epochs. Prothero begins with the \"greenhouse of the dinosaurs,\" the global-warming episode that dominated the Age of Dinosaurs and the early Age of Mammals. He describes the remarkable creatures that once populated the earth and draws on his experiences collecting fossils in the Big Badlands of South Dakota to sketch their world. Prothero then discusses the growth of the first Antarctic glaciers, which marked the Eocene-Oligocene transition, and shares his own anecdotes of excavations and controversies among colleagues that have shaped our understanding of the contemporary and prehistoric world. The volume concludes with observations about Nisqually Glacier and other locations that show how global warming is happening much quicker than previously predicted, irrevocably changing the balance of the earth's thermostat. Engaging scientists and general readers alike,Greenhouse of the Dinosaursconnects events across thousands of millennia to make clear the human threat to natural climate change.

For 65 million years dinosaurs ruled the Earth-until a deadly asteroid forced their extinction. But what accounts for the incredible longevity of dinosaurs? A renowned scientist now provides a startling explanation that is rewriting the history of the Age of Dinosaurs. Dinosaurs were pretty amazing creatures-real-life monsters that have the power to fascinate us. And their fiery Hollywood ending only serves to make the story that much more dramatic. But fossil evidence demonstrates that dinosaurs survived several mass extinctions, and were seemingly unaffected by catastrophes that decimated most other life on Earth. What could explain their uncanny ability to endure through the ages? Biologist and earth scientist Peter Ward now accounts for the remarkable indestructibility of dinosaurs by connecting their unusual respiration system with their ability to adapt to Earth's changing environment-a system that was ultimately bequeathed to their descendants, birds. By tracing the evolutionary path back through time and carefully connecting the dots from birds to dinosaurs, Ward describes the unique form of breathing shared by these two distant relatives and demonstrates how this simple but remarkable characteristic provides the elusive explanation to a question that has thus far stumped scientists. Nothing short of revolutionary in its bold presentation of an astonishing theory, Out of Thin Air is a story of science at the edge of discovery. Ward is an outstanding guide to the process of scientific detection. Audacious and innovative in his thinking, meticulous and thoroughly detailed in his research, only a scientist of his caliber is capable of telling this surprising story.

\"Radioactivity is like a clock that never needs adjusting,\" writes Doug Macdougall. \"It would be hard to design a more reliable timekeeper.\" In Nature's Clocks, Macdougall tells how scientists who were seeking to understand the past arrived at the ingenious techniques they now use to determine the age of objects and organisms. By examining radiocarbon (C-14) dating—the best known of these methods—and several other techniques that geologists use to decode the distant past, Macdougall unwraps the last century's advances, explaining how they reveal the age of our fossil ancestors such as \"Lucy,\" the timing of the dinosaurs' extinction, and the precise ages of tiny mineral grains that date from the beginning of the earth's history. In lively and accessible prose, he describes how the science of geochronology has developed and flourished. Relating these advances through the stories of the scientists themselves—James Hutton, William Smith, Arthur Holmes, Ernest Rutherford, Willard Libby, and Clair Patterson—Macdougall shows how they used ingenuity and inspiration to construct one of modern science's most significant accomplishments: a timescale for the earth's evolution and human prehistory.

Lawson’s (Lawson, A.: 2004, Science & Education, 13, 155–177) analysis of the meteorite hypothesis of dinosaur extinction exhibits flaws similar to his earlier (2002) analysis of Galileo’s discovery of Jupiter’s moons (Allchin, D.: 2003, Science & Education, 12, 315–329).

The disappearance of nonavian dinosaurs is probably the most notorious extinction event of all time, yet it is only a small part of a greater class of extinctions known as “mass extinctions.” Mass extinctions are global events characterized by unusually high rates of extinction. The magnitude of these rates is usually unspecified but it is generally significantly higher than the rate of so-called “background extinctions”; that is, extinctions that occur constantly through geologic time (Raup and Sepkoski 1982). Mass extinctions are also characterized by geologically short timescales and by a significant diminution in the number of surviving taxa, as well

The federal government was hopelessly in a dilemma about nuclear winter, concerned that it might force a reconsideration of its national policy. The military was less apprehensive, recognizing quite early the significance of these studies and showing a willingness to obtain honest advice. In 1982, the National Academy of Sciences was conducting a study to evaluate the link between dinosaur extinction and dust, rather than nuclear winter. Meanwhile, the Department of the Navy, always technologically oriented, made its own efforts to keep informed about nuclear winter. In 1983, Carl Sagan advocated “minimal deterrence” and encouraged a “build-down” to the approximate nuclear winter threshold level of 100 MT by the end of the century. He also presented a layman’s summary of the physical and biological consequences of nuclear war as recently determined by his TTAPS team (comprised of Richard Turco, Owen Brian Toon, Thomas Ackerman, James Pollack, and himself) and their colleagues.

This is a review of recent media publications and journal articles about evolution and paleontology.

This chapter contains sections titled: Dinosaur Diversity Dinosaur Disparity Dinosaur Molecular Evolution The Grand Narrative of Dinosaur Evolution Dinosaur Extinction Conclusions

Whether or not nonavian dinosaur biodiversity declined prior to the end-Cretaceous mass extinction remains controversial as the result of sampling biases in the fossil record, differences in the analytical approaches used, and the rarity of high-precision geochronological dating of dinosaur fossils. Using magnetostratigraphy, cyclostratigraphy, and biostratigraphy, we establish a high-resolution geochronological framework for the fossil-rich Late Cretaceous sedimentary sequence in the Shanyang Basin of central China. We have found only three dinosaurian eggshell taxa (Macroolithus yaotunensis, Elongatoolithus elongatus, and Stromatoolithus pinglingensis) representing two clades (Oviraptoridae and Hadrosauridae) in sediments deposited between ∼68.2 and ∼66.4 million y ago, indicating sustained low dinosaur biodiversity, and that assessment is consistent with the known skeletal remains in the Shanyang and surrounding basins of central China. Along with the dinosaur eggshell records from eastern and southern China, we find a decline in dinosaur biodiversity from the Campanian to theMaastrichtian. Our results support a long-term decline in global dinosaur biodiversity prior to 66 million y ago, which likely set the stage for the end-Cretaceous nonavian dinosaur mass extinction.