Bird
Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. Extant birds have wings; the most recent species without wings was the moa, which is generally considered to have become extinct in the 16th century. Wings are evolved forelimbs, and most bird species can fly. Many species are economically important, mostly as game or poultry. Evolution and classification Definition Aves and a sister group, the clade Crocodilia, contain the only living representatives of the reptile clade Archosauria. Gauthier[8] identified four conflicting ways of defining the term "Aves", which is a problem because the same biological name is being used four different ways. Under the fourth definition Archaeopteryx is an avialan, and not a member of Aves. Most researchers define Avialae as branch-based clade, though definitions vary. Dinosaurs and the origin of birds Early diversity
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Adrienne Mayor
Adrienne Mayor (born 1946) is a historian of ancient science and a classical folklorist. Mayor specializes in ancient history and the study of "folk science": how pre-scientific cultures interpreted data about the natural world, and how these interpretations form the basis of many ancient myths, folklore and popular beliefs. Her work in pre-scientific fossil discoveries and traditional interpretations of paleontological remains has opened up a new field within the emerging discipline of geomythology and classical folklore. Mayor's book on the origins of biological and chemical warfare revealed the ancient roots of poison weaponry and tactics. Since 2006, Mayor has been a research scholar in the Classics Department and the History and Philosophy of Science and Technology Program at Stanford University. Bibliography[edit] The First Fossil Hunters (2000, reissued with new Introduction 2011)[edit] Other highlights include: Fossil Legends of the First Americans (2005)[edit] Books[edit]
Cretaceous
The Cretaceous (/krɨˈteɪʃəs/, krə-TAY-shəs), derived from the Latin "creta" (chalk), usually abbreviated K for its German translation Kreide (chalk), is a geologic period and system from circa 145 ± 4 to 66 million years (Ma) ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the Cenozoic era. It is the last period of the Mesozoic Era, and, spanning 79 million years, the longest period of the Phanerozoic Eon. Geology[edit] Key events in the Cretaceous An approximate timescale of key Cretaceous events. Research history[edit] Stratigraphic subdivisions[edit] As with other older geologic periods, the rock beds of the Cretaceous are well identified but the exact ages of the system's base is uncertain by a few million years. Rock formations[edit] The high eustatic sea level and warm climate of the Cretaceous meant a large area of the continents was covered by warm shallow seas. Paleogeography[edit] Climate[edit] Life[edit]
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Jurassic
Etymology[edit] The chronostratigraphic term "Jurassic" is directly linked to the Jura Mountains. Alexander von Humboldt recognized the mainly limestone dominated mountain range of the Jura Mountains as a separate formation that had not been included in the established stratigraphic system defined by Abraham Gottlob Werner, and he named it "Jurakalk" in 1795.[4][5][6][7] The name "Jura" is derived from the Celtic root "jor", which was Latinised into "juria", meaning forest (i.e., "Jura" is forest mountains).[5][6][8] Divisions[edit] Key events in the Jurassic An approximate timescale of key Jurassic events. Various dinosaurs roamed forests of similarly large conifers during the Jurassic period. Paleogeography and tectonics[edit] During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Gulf of Mexico opened in the new rift between North America and what is now Mexico's Yucatan Peninsula.
Dinosaures (TV Series 1991–1994
Triassic
The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it would take well into the middle of the period for life to recover its former diversity. Therapsids and archosaurs were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs, dinosaurs, first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic.[5] The first true mammals, themselves a specialized subgroup of Therapsids also evolved during this period, as well as the first flying vertebrates, the pterosaurs, who like the dinosaurs were a specialized subgroup of archosaurs. The vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry,[6] with deserts spanning much of Pangaea's interior. Dating and subdivisions[edit]
when i was 5 i loved dinos
Mesozoic
The Mesozoic era /mɛzɵˈzoʊɪk/ is an interval of geological time from about 252 to 66 million years ago. It is also called the age of reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by reptiles such as Iguanadon, Megalosaurus, Plesiosaurus and what are now called Pseudosuchia.[1] The era began in the wake of the Permian–Triassic extinction event, the largest well-documented mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction which is known for having killed off non-avian dinosaurs, as well as other plant and animal species. The Mesozoic was a time of significant tectonic, climate and evolutionary activity. The era witnessed the gradual rifting of the supercontinent Pangaea into separate landmasses that would eventually move into their current positions. The climate of the Mesozoic was varied, alternating between warming and cooling periods. Geologic periods[edit]
i always loved cars
in 7th grade i played for track at redlion
