Cretaceous-+Locito

__ **Cretaceous Period** __

===  I n prehistoric times the earth was divided by Eras and Periods. There were 3 Eras and each era was divided by periods each with individual occurrences. I have researched the Cretaceous Period. During the c retaceous period the dominant creatures were the dinosaurs. Mammals and reptiles and flowering plants were developed. Towards the end of my period all dinosaurs were extinct due to an asteroid that hit earth. Before me there was another period called the Jurassic Period. Throughout the Jurassic period the continents started breaking apart, the sea levels were high, and they had lots of volcanic activity. After the Cretaceous period the Tertiary period followed. Tertiary had no more dinosaurs due to the mass extinction from cretaceous. They consisted of marine mammals but at the same time land mammals were developing. ===

=== Modern times have a great impact from prehistoric time because of the plate tectonics and the continental movement. Throughout the cretaceous period the continents were still moving apart from each other. North America was nearly formed completely. The latitude and longitude was almost the same as it is today be cause almost all the continents were in place. The seasons began to grow more distinct due to the weathers cool down. ===

Massachusetts was almost in place, almost in the same latitude it is today.
 = For scientist to know all this information about prehistoric time they need evidence. There main evidence is a fossil. Fossils are very important to scientist because of all the information they collect from them. Most fossils about my period are found around Red Deer River Valley, Southeast Alberta, Canada. Scientists have found many fossils about my period, animals, and plants. Three of the many fossils found are, Hypacrosaurus @ 2008 Royal Tyrrell Museum, Lambeosaures @ 2008 Royal Tyrrell Museum, Maiasaura Peeblesorum, @ 2005 Museum of Rockies. The landform that was forming was the Himalayan Mountains, due to the continents crashing in to each other. = = = ==

= = = = ==== The earth has not been dominated my humans through all its lifetime. In the cretaceous period the dominant life form were the dinosaurs. Even though the dominant creatures were dinosaurs there was many other living things.Many new groups of organisms (plants and animals) evolved during the Cretaceous. Near the beginning of the Cretaceous, around 120 million years ago, new groups of dinosaurs originated, including ceratopsians (plant-eating dinosaurs with horns on the head, such as //Triceratops//), pachycephalosaurs (smaller dome-headed, plant-eating dinosaurs), and hadrosaurs (‘duck-billed’ dinosaurs such as //Edmontosaurus//). The earliest marsupial, monotreme, and placental mammals appeared during the middle part of the Cretaceous. In addition, a now-extinct group of rodent-like forms, the multituberculates, known from the Jurassic, had become common in Asia and North America. Although many types of mammals were present, they were a relatively inconspicuous part of the fauna until the succeeding Paleocene Epoch. The first birds had appeared in the Late Jurassic, but they began to diversify during the Cretaceous. They still shared the skies with flying reptiles, the pterosaurs. Terrestrial reptiles such as snakes, lizards, and sphenodontians became more common as well. ====

=Check out websites about Cretaceous; =
 * [|Ucmp] ** ** [|Cretaceous] **

= Check out my Reflection =