Saturday, March 21, 2020

Cretaceous Period Essay Example

Cretaceous Period Essay Example Cretaceous Period Essay Cretaceous Period Essay The Cretaceous period was 144-65 million years ago. It was the last period of the Mesozoic era. The Cretaceous period was first defined by a Belgian geologist named Jean d’Omalius d’Halloy in 1882, using the strata in the Paris Basin and named for the extensive beds of chalk (calcium carbonate deposited by shells of marine invertebrates, principally coccoliths), found in the upper Cretaceous of Europe. The name Cretaceous was derived from latin creta, meaning chalk. The name of the island, Crete, has the same origin. The Cretaceous period had a relatively warm climate and high eustatic sea level. The oceans and seas were populated with now extinct marine reptiles and on the land, dinosaurs. And at the same time mammals, birds, and flowering plants appeared. Flowering plants spread during this period although they did not become predominant until the Campanian stage near the end of the epoch. Therid evolution was aided by the first appearance of bees. At the same time, some earlier Mesozoic gymnosperms like Conifers continued to thrive. On land, mammals were a small and still relatively minor component of the fauna. The fauna was dominated by the Archosaurian reptiles, especially dinosaurs which were the most diverse. Pterosaurs were common in the early and middle time of the period, but as the Cretaceous proceeded they faced growing competition from the radiation of birds, and by the end by the end of the period, only tow specialized families remained. During the Cretaceous, insects began to diversify, and the oldest known ants, termites, butterflies, moths, grasshoppers and wasps appeared. In the seas, rays, modern sharks and teleosts became common. Marine reptiles such as the ichthysosaurs were in the early to middle time of the Cretaceous, plesiosaurs throughout the entire period, and mososaurs in the late Cretaceous. There was a progressive decline in biodiversity during the Maastrichtian stage of the Cretaceous period prior to the suggested ecological crisis induced by the events of the mass extinction. Biodiversity required a substantial amount of time to recover from the events of the mass extinction, despite the probable extinction of many species. Despite the severity of this boundary event, there was a significant variability in the rate of extinction between and within different fossils. Species which depended on photosynthesis declined or became extinct due to the reduction of solar energy reaching the Earth’s surface because of atmospheric particles blocking the way of sunlight. Evidence suggests that herbivorous animals, which depended on plants as their food, died out because as their food sources became scarce. Consequently, top predators, such as the Tyrannosaurus Rex also perished.

Thursday, March 5, 2020

Great Essays

Great Essays Great Essays Great Essays Great essays are not easy to write, but if you are interested in the topic and if you feel inspired, you have no barriers to creating great essays.   Read the following sample of great essay.   It is well-written and will definitely gain your attention. If you have an academic assignment to write the great essay, feel free to request our custom essay writing service at any time. Our writers are working 24/7 without weekends to lend you a hand of help with any essay writing. Great Essays Sample The most important of parental allies was the nurse. It was the almost unanimous opinion of churchmen, doctors, and moralists from Erasmus on that mothers ought to breastfeed their own infants. Some theologians even tried to suggest that a failure to do so should be regarded as a mortal sin. At the same time, these writers would reluctantly add some words of advice on how to choose a nurse, a last-minute concession indicating that the practice was far too strongly entrenched in the mores of the period to be dislodged by the exhortations of a few intellectuals. In this respect, Rousseau, who has always been regarded as the revolutionary champion of maternal breastfeeding, was no less sensitive to custom than his predecessors, and his passionate appeal to mothers was followed by some sober recommendations for selecting a nurse, and even a touch of lyricism on the joys of nursing in the fresh air of the countryside. In this section, I describe the deeply rooted practice of employing nur ses, and explore some of the possible reasons for their participation in family life. The first point to note about the nurse is her poverty. "All the women who hire themselves out as nurses are peasants or women of mean estate." By contrast, the family which employed her necessarily belonged to a relatively affluent class. FranÃÆ' §ois Mauriceau noted that poor people did not even have the means to hire a nurse for the first week of the baby's life, during which time he believed the mother's own milk was not good for the infant. These women would have to breastfeed their children themselves right from the beginning. There was no possibility of help even for a brief period. He went on to single out among the people who engaged nurses "all the women of quality and a majority of the bourgeoisie." The relationship of the nurse to her employers varied with circumstances. The woman might be a long-term domestic of the parents, perhaps the nurse of earlier children from the same family. In many cases, however, she was a stranger. In Paris, placement bureaus arranged connections between nurses and families interested in doing business. Many writers deplored the frequent failure of mothers to investigate the character of the women they were choosing to feed their offspring. In spite of the doctors' urgings, this choice was often not made in advance of the birth. Where details are given, the parents, even those who seem especially thoughtful and attentive to the welfare of their children, contracted with the nurse after the baby had been delivered. Sometimes the father of the infant gave the money directly to the nurse's husband. Great Essays Writing Service What is the first step of great essays writing?   Writing an essay, you should pay attention to the format and flow of ideas.   If you cannot afford spending hours of your time in libraries, order professional customized writing assistance at our site.   Our writers are able to impress you with custom written essays!   Our prices are impressively low while the quality of written essays is unquestionably high. is a trusted and reliable online service.