Our studies using American alligators, Alligator mississippiensis, green turtles, Chelonia mydas, and leatherback turtles, Dermochelys coriacea, have provided insights into the physiology of large extant and extinct reptiles. Respiratory and metabolic physiology studies indicate that many living large reptiles exhibit heat conservation adaptations and mechanisms which allow them to maintain constant warm body temperatures in cold environments with low “reptilian” metabolism. For example, leatherback turtles which are found in the oceans as far north as the Arctic Circle can maintain constant body temperatures above 25° C while water temperatures are below 7° C. This dramatic ability to maintain warm temperatures in cold, highly conductive water, that would quickly cause hypothermia and kill most endotherms, is made possible by a mechanism we describe as gigantothermy. Gigantothermy is the ability to maintain constant warm body temperatures with low energy consumption, control of peripheral circulation and extensive insulation due to large body size.

The muscles of leatherbacks show a fiber type unlike the specialized, endothermic heater organs of modern fish Scombroidei (tunas, billfish, bonitos, butterfly mackerel and relatives) that have evolved specialized “endotherm like” red muscle to maintain regional endothermy. The primitive large reptiles like leatherbacks do not show the specialization in muscle fiber type nor do the enzyme activities indicate the emergence or evolution of endothermy or a high rate of energy consumption. Yet leatherbacks can migrate over 70 km per day in the open ocean and dive to depths deeper than 1000 m on a regular basis.

Collectively these physiological studies on large living reptiles support the concept that dinosaurs, especially the larger more spectacular species, were able to maintain high body temperatures, be very active, move great distances quickly, as well as exhibit complex behavior such as communal nesting and nest building without evolving endothermy or high levels of energy consumption. The physiology of large living reptiles indicates that it is not necessary to attribute heretical ideas to explain the paleophysiology and capabilities of dinosaurs. As reptiles they were fully capable of complex and spectacular behaviors such as long and rapid migrations and surviving the cold. All evolutionary indications suggest that large size would provide a negative selection pressure for the development of endothermy especially in equable and or tropical climates.

Dinosaurs, medicine, and pathology and have long been intertwined. A family physician, Gideon Algernon Mantell, found the first English dinosaur, while making house calls (Rothschild and Martin, 1993). This was 19 years prior to Sir Richard Owen's first use of the name, dinosaur in 1841. The Carnegie Museum's acquisition of its superb Tyrannosaurus rex skeleton was the result of another form of pathology. Fear that Hitler would bomb New York City led The American Museum of Natural History to transfer one of its two tyrannosaurs (to safeguard the genus).

Every once in a while, prospecting paleontologists happen upon distinctive fossil blobs with vaguely familiar shapes. They are usually sausage-shaped or roundish, and are made of material that is clearly not just bone or parent sediment These unusual formations are fossil feces—also known as coprolites. They were produced by fish, crocodiles, and mammals, and some were produced by dinosaurs.

For at least 10 millenia, a special mystique has surrounded amber. This is probably due to the warmth of its color and touch, its lightness, and the small organisms that are sometimes found in it. Some of the oldest Mesolithic artifacts are amber carvings from Europe, and a rich folklore about origins of amber existed among the ancient Greeks, Assyrians, and Romans. The true origins of amber, as a fossilized resin that bled from trees, was first recognized by the Roman natural historian, Pliny the Elder. By the Renaissance Period, amber was used for elaborate figurines, carved bowls, jewelry, pipes, even caskets. The color of amber, especially in Mediterranean cultures, represented luxury.

The movie Jurassic Park has engendered much excitement and some speculation among both the general public and the scientific community as to the possibilities of genetic research and molecular preservation.

But will the dinosaurs “rise” again? Will scientists be able to ‘clone’ a dinosaur out of bits of genetic material and once again unleash these great beasts to walk the earth? If it is possible, should it be attempted? If not, why are time, money and effort being expended by several groups of investigators in attempts to isolate and characterize the DNA of these extinct creatures, if such DNA can possibly still exist? What can we hope to learn from these efforts, should they be fruitful?

During the latest Cretaceous, before the demise of the last dinosaur, there were ferns, palm trees, and crocodiles in what is now desert in New Mexico, Seymour Island in Antarctica, and the Gobi Desert. Then things changed. Ferns, palm trees, and crocodiles no longer live in New Mexico, Antarctica, or the Gobi Desert because the climate changed. Throughout the 4.6 billion year history of the Earth, internal and external forces have caused changes in the very thin surface layer of the Earth where life exists.

This is an exciting era to be a scientist, due to the increasing levels of technology available to us; particularly due to the advances that have been made in the field of computer science. Advances in electronic technology have made computer hardware very powerful and affordable, while advances in software design and human/computer interfaces have made computers more natural to use. Computers have been utilized in nearly every field of scientific study, permitting new levels of development in those fields that wouldn't be possible otherwise. Computer graphics are useful visualization tools that help scientists understand complex data, and convey ideas to others.

The process of photosynthesis is critical to the existence of almost all the Earth's ecosystems by providing the fundamental mechanism through which the Sun's energy is harnessed to convert carbon dioxide and water into sugars and oxygen. These sugars ultimately provide the basic source of energy (primary production) on which most life depends. In terrestrial ecosystems macroscopic land plants are responsible for virtually all primary production and therefore provide the basic sustenance that supports all land animals, either directly or indirectly. An accurate knowledge of Mesozoic plants and vegetation is therefore critical to understanding the ecology of dinosaurs and the ecosystems in which they flourished. Similarly, because large herbivorous dinosaurs must have exerted a major influence on terrestrial ecosystems some knowledge of dinosaur biology is crucial to understanding the ecological pressures to which Mesozoic plants were subjected. Because there is also a close correlation between the climate of an area and the kind of vegetation that it supports, fossil plants also provide important evidence on the paleoclimates of the dinosaur world.

In recent years paleontology has witnessed explosive popularity in schools at all grade levels as well as among the general public. It is ironic that although paleontology continues to receive such interest and attention, teaching and research programs at universities, industry, museums and elsewhere are in decline with fewer positions committed to paleontology and less interest in collecting or storing fossils. Yet, the fact remains that paleontology is a cornerstone of geologic and evolutionary science, as well as having important contributions to make towards discovering and evaluating natural resources. The truths recognized more than a century ago by F. B. Meek and A. H. Worthen (1866), although written in a style that belies its age, are still appropriate:

“When it is therefore borne in mind, that coal and other valuable minerals were not indiscriminately distributed through the earth, but were mainly formed or deposited, at least in quantities and under conditions to be useful to man, during particular geological periods, the importance of knowing to what epoch of the earth's history the rocks of any given district belong, before undertaking mining enterprises of any kind, will be readily understood, and the intelligent general reader will at once comprehend why it is that geologists give so much attention to fossils. In short, the first and most important step in the prosecution of a geological survey, is a careful and thorough study and investigation of the organic remains found in every seam and stratum of the rocks of the district to be explored; for without a knowledge of these, all conclusions in regard to the geological structure of the country, or of the age and position in the geological column of its rocks, must necessarily be vague and unreliable. Indeed, without the aid of Palaeontology, Geology would scarcely be entitled to rank as a science at all.”

I was eleven years old when I read a book by Roy Chapman Andrews (1953) that changed my life. It was a book about dinosaurs, those magnificent animals that had captured my interest when I was even younger. But more significantly, the book was about looking for the remains of these ancient dragons in the Gobi Desert of China and Mongolia, and for the first time I learned that there was a potential career in hunting dinosaurs. The day I read the book was the day I decided to become a paleontologist. But in my wildest dreams I never imagined that I would follow in the footsteps of Andrews and end up in the Gobi Desert.

Australia has a scant but significant record of dinosaurs which includes a prosauropod, two or three sauropods, at least four theropods (including carnosaurs and an ornithomimosaur), four hypsilophodontids, an aberrant iguanodont, a primitive thyreophoran (possibly an ankylosaur), and a possible primitive neoceratopsian. Footprint fossils indicate higher taxonomic diversity, including small bipedal ornithopods and coelurosaurs, very large sauropods, large carnosaurs, and a stegosaur. The most diverse dinosaur assemblage, from the Early Cretaceous of Victoria, represents a polar dinosaur community that lived within the Cretaceous Antarctic Circle.

That dinosaurs have been extinct for 65 million years is a well established fact of paleontology. But determining why dinosaurs (other than birds) became extinct has been a difficult problem for science.

The present Cretaceous/Tertiary extinction debate started with findings by Alvarez et al. (1980) of enhanced levels of iridium at K/T sections in Italy, Denmark and New Zealand. They postulated that the iridium was extraterrestrial in origin and related to a 10 km diameter asteroid impact which would have produced a crater some 200 km in diameter. They further suggested that a giant dust cloud would have been injected into the stratosphere from the impact with a residence time of several years and that the resulting darkness would have suppressed photosynthesis with a consequent elimination of succeeding members in the biological food chain — ergo, a mass extinction event.

Mass extinction is characterized by the loss of more than 50 percent of the world's species within a short interval of geologic time - months to as much as 3 million years (My). In the fossil record, these events have primarily been recorded from the marine realm. Three patterns of mass extinction have been described - catastrophic, stepwise, and graded extinction. Many well-studied extinction intervals contain elements of more than one pattern, suggesting that these biotic crises were caused by varied forcing mechanisms linked by complex environmental feedback loops. This hypothesis is supported by the discovery that the four well-studied Phanerozoic mass extinctions (Late Devonian, middle and terminal Cretaceous, Eocene-Oligocene boundary extinctions) share a number of physical, chemical, and biological characteristics in common. They consistently show stepwise extinction patterns linked to intervals of extraordinary fluctuations in the temperature, chemistry and structure of ocean-climate systems, at rates and magnitudes well above background levels. In addition, tropical ecosystems were the first and most severely affected, and more poleward, temperate biotas were mainly stressed during the later phases of the extinction interval. Evidence for these unusual environmental changes is derived from high-resolution (cm-scale) paleobiological, sedimentological, trace-element and stable-isotope analyses spanning mass extinction intervals. These dramatic environmental fluctuations were the immediate causes of mass extinction, as they progressively exceeded the survival limits of global biotas largely adapted to warm, equable, ice-free climates which characterized over 90 percent of Phanerozoic time. These environmental fluctuations probably represented feedback phenomena from more powerful, short-term forcing mechanisms which abruptly perturbed the structure of ocean-climate systems. Multiple impacts of extraterrestrial objects within short (<1-3 My) time intervals - so-called meteorite/comet showers - are the most logical candidates. This hypothesis is supported by physical and chemical evidence for impacts clustered around most, but not all, Mesozoic and Cenozoic mass extinctions.

Death of an organism is a very personal event. The extinction of a species is viewed as catastrophic, only if one is a member of that species. In fact, the extinction of a species simply represents the sum total of deaths of individuals within the species during a time interval in which the rate of death exceeds the rate of recruitment of new individuals. That is, the population size within the species declines to the point that the unit is no longer reproductively viable.

During the past decade, the scientific community, media and general public have witnessed one of most fascinating scientific debates of the century concerning the extinction at the end of the Cretaceous that resulted in the demise of the dinosaurs. It is doubtful that, if dinosaurs had not been among the principal characters, the Terminal Cretaceous Extinction Event (TCEE) would have received such close attention. The fact that so much attention has been given to dinosaur extinction when in fact, they played only a minor role in the TCEE, has shifted the focus away from more fundamental unresolved questions concerning this profound biotic event 65 mya (million years ago).