The first theory of the dinosaur extinction
The K-T theory
The K-T boundary extinction event took place 65,000,000
years ago, and is merely one in a long line of mass extinction
events. The chief reason for its fame is that it ushered out
those perennially popular beasts, the dinosaurs. Many
explanations have been given for this mass extinction, the
most widely known being a massive impact caused by a
bolide, or meteorite (meteorites are meteors which have
impacted on the surface of a planet or other body). This idea
has proved popular with television programme makers and
the general public alike. This is probably because 1,000 years
of C02 poisoning by wide-ranging volcano systems lacks the
dramatic effect and neat ending produced by computer
generated acts of planetary penetration.
Volcano Chain Reaction
Theory: Some believe that the large numbers of
volcanoes was having the largest chain reaction ever
seen. Every single volcano at that time should have
become active and then the lava would kill the dinosaur.
Conflict: A volcano chain reaction is rather unrealistic.
What are the odds of all the volcanoes should become
active at one time. Why was the fish and the mammals
not killed, a worldwide volcano chain reaction would
defiantly kill all species on earth.
• Did a collision with a giant asteroid or comet change the shape of life on
Earth forever?
• It is widely agreed that such an object -- 10 kilometres across -- struck
just off the coast of the Yucatan peninsula 65 million years ago.
• According to scientists who maintain that dinosaur extinction came
quickly, the impact must have spelled the cataclysmic end.
• For months, scientists conclude, dense clouds of dust blocked the sun's
rays, darkening and chilling Earth to deadly levels for most plants and, in
turn, many animals. Then, when the dust finally settled, greenhouse
gases created by the impact caused temperatures to skyrocket above
pre-impact levels.
• In just a few years, according to this hypothesis, these frigid and
sweltering climatic extremes caused the extinction of not just the
dinosaurs, but of up to 70 percent of all plants and animals living at the
time.
Ice age
Theory: An ice age could have
come and then all the dinosaurs
would freeze to death.
Conflict: Scientist have not found
a single trace of ice age in the
period the dinosaurs lived
http://www.bbc.co.uk/dna/h2g2/A706862
http://library.thinkquest.org/22973/library/dieout.htm
http://web.ukonline.co.uk/a.buckley/dino.htm