jueves, 29 de mayo de 2008

SAHARA DESERT



“The Great Desert”, is the world's largest hot desert and the world's second largest desert after Antarctica. At over 9,000,000 square kilometers, it covers most parts of northern Africa; an area stretching from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean. It is almost as large as the continental United States, and is larger than Australia. The Sahara has an intermittent history that may go back as much as 3 million years.
The boundaries of the Sahara are the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea and Egypt on the east, and the Sudan and the valley of the Niger River on the south.
The climate of the Sahara has undergone enormous variation between wet and dry over the last few hundred thousand years.[16] During the last ice age, the Sahara was bigger than it is today, extending south beyond its current boundaries.
Fauna
• The Leiurus quinquestriatus (aka Deathstalker) scorpion which can be 10 cm long. Its Agitoxin and Scyllatoxin, toxins contained within the venom, are fatal in the majority of cases.

• Sand vipers, which average less than 50 cm in length. Many have a pair of horns, one over each eye. Active at night, they usually lie buried in the sand with only their eyes visible. Bites are painful, but rarely fatal.

• The fennec, an omnivore.

• The hyrax. It first appears in the fossil record over 40 million years ago, and for many millions of years hyraxes were the primary terrestrial herbivore in Africa.
Andrea Marcela Rojas Correa
Code: 200620857
Medicine
Group: 10

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