ASW 8 Science C Block

The climate of the Triassic era was influenced by Pangaea, its centralized position stradling the equator, and the geologic activity associated with its breakup. Generally speaking, the continents were of high elevation compared to sea level, and the sea level did not change drastically during the period. Due to the low sea level, flooding of the continents to form shallow seas did not occur. Much of the inland area was isolated from the cooling and moist effects of the ocean. The result was a globally arid and dry climate, though regions near the coast most likely experienced seasonal monsoons. There were no polar ice caps, and the temperature gradient in the north-south direction is assumed to have been more gradual than present day. The sea level rose as the rift grew between North Africa and southern Europe, resulting in the flooding of Central and South Europe; the climates of terrestrial Europe were hot and dry, as in the Permian. Overall, it appears that the climate included both arid dune environments and moist river and lake habitats with gymnosperm forests.

rming on the Americas, North Africa was being split from Europe by the spreading rift. This division of the continents advanced further westward, eventually splitting eastern North America from North Africa.

The Triassic Period was the first period of the Mesozoic Era and occurred between 251 million and 199 million years ago

Climate was generally very dry over much of Pangaea with very hot summers and cold winters in the continental interior.

won't

These three layers make up a sort of 3-layer cake. Just like a cake, the bottom layer went down first, followed by the middle and the top.

Found between 3.85 and 2.95 million years ago in Eastern Africa (Ethiopia, Kenya, Tanzania),

Similar to chimpanzees, Au. afarensis children grew rapidly after birth and reached adulthood earlier than modern humans. This meant Au. afarensis had a shorter period of growing up than modern humans have today, leaving them less time for parental guidance and socialization during childhood.

Au. afarensis had both ape and human characteristics: members of this species had apelike face proportions (a flat nose, a strongly projecting lower jaw) and braincase (with a small brain, usually less than 500 cubic centimeters -- about 1/3 the size of a modern human brain)

five-ton animal the size of a car, with a giant bony frill on its head, and you've got a fairly accurate picture of a ceratopsian dinosaur such as Triceratops.

are found only in the Late Cretaceous of North America; they are among the last of the dinosaurs (other than the birds of course).

Ceratopsians were ornithischians, or "bird-hipped" dinosaurs.

It was during the Paleoproterozoic that small islands of crust were first stitched together to form the stable nuclei of the continents we know today.

India has a similar history. Similarly, India appears to be an amalgamation of four cratons.

The formation of Baltica - the continent which was to become Europe -- is one of the best-known examples. Baltica formed in the Paleoproterozoic from the fusion of three cratons

Table of Contents IntroductionThe Quaternary environmentGlaciationSea-level changesPaleoclimate

The most distinctive changes seen during the Quaternary were the advances of ice into temperate latitudes of the Northern Hemisphere.

The glacial landscapes were dominated by ice several kilometres thick that covered all but the highest peaks in the interior.

There were no dinosaurs at the beginning of the Triassic, but there were many amphibians and some reptiles and dicynodonts (like Lystrosaurus). During the early Triassic, corals appeared and ammonites recovered from the Permian extinction. Seed plants dominated the land; in the Northern hemisphere, conifers flourish. Glossopteris was the dominant southern hemisphere tree during the Early Triassic period.

The beginning of the Paleogene Period was very warm and moist compared to today’s climate. Much of the earth was tropical or sub-tropical. Palm trees grew as far north as Greenland!

By the end of the Paleogene, during the Oligocene Epoch, the climate began to cool.

During the Late Cretaceous, the high levels of atmospheric carbon dioxide heated up the Earth in the same way as they do today.

About 65 million years ago the second greatest mass extinction in Earth history occurred, resulting in the loss of the dinosaurs as well as nearly 50% of all the world’s species. Though not nearly as severe as the end-Permian mass extinction, the end-Cretaceous extinction is the most famous mass extinction in Earth history

Terrestrial plants also suffered a major extinction at this time; in some regions up to 60% of latest Cretaceous plant species were absent in the subsequent Paleocene.

The causes of the end-Cretaceous extinction are still being debated by paleontologists. Researchers agree that a major factor was an asteroid about 10 kilometers in diameter that struck what is now the Yucatán peninsula in Mexico. The effects of the impact were catastrophic, probably including global forest fires, possibly a period of cold weather due to sunlight-blocking dust and smoke, and a subsequent period of hot climate caused by the high levels of CO2 released into the atmosphere by the impact.