Transcript What Happened to the Dinosaurs?

What Happened to the
Dinosaurs?
February 24th, 2015
Mystery
• What do we need when we are trying to solve
a mystery?
Theories
• Mammal competition
• Could the mammals have outcompeted
dinosaurs for food resources?
Theories
• Lots of Volcanism
• Evidence for massive beds of ancient lava
found all around the world around 65 to 70
million years ago
Theories
• Plate Tectonics
• Repositioning of the world’s landmasses was
disastrous for dinosaurs. As mountains
formed, ocean
currents were
redirected and world
sea level fell
Theories
• An asteroid
• Ok…but
where is the
evidence?
Evidence
• In 1981 two scientists Walter and his son Luis Alvarez find a
very strange layer of iridium in Italy at
the Cretaceous and Paleogene periods
around 65 million years ago.
• They found this same layer all over
the world.
Evidence
• Iridium is a metal that is very rare on Earth’s surface
but is commonly found in asteroids
• The layer of iridium at the Cretaceous Paleogene
boundary had 100 X more Iridium than normal
If There Was an Asteroid Then There
Must Be…
• An impact crater
Around the Same Time (1978)…
• A scientist working for a Mexican oil company was
looking for new places to drill for oil using radar
• In his searching, he found a perfectly circular ring
that is 70 km (40 miles) across under the ocean.
Let’s Go Down and Test Those Rocks!
• They tested the rocks and found them to be
about 65 million years old, the same time as
the Cretaceous-Paleogene extinction event
How Big Was The Asteroid?
• If the size of the crater was 70 km across…that
must mean that the size of the asteroid was…
So if a Rock this Big Would Hit Earth
What Would Happened?
Let’s Watch a Video…
• http://www.history.com/topics/why-did-thedinosaurs-die-out
Content Take-Away
• Dinosaurs went extinct because of more than
1 reason:
• There was climate changes because of plate
tectonic movement
• Lots of volcanism
• Competition by mammals
• Big asteroid
impact did NOT
help…
Unison Reading Groups Section 1
Group A
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Group C
Group D
Group E
Alimatou
Sandeilis
Daiana
Antoneta
Reyson
Henood
Sharna
Thanya
Nathi
Caroline
Misha
Sadia
Kimby
Gabriela
Katerina
Khady
Maisha
Megany
Harold
Obniel
Robert
Keyzie
Unison Reading Groups Section 2
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Anam
Jubayer
Ramzi
Mosammat
Dayana
Perla
Ibrahim
Jennifer
Seme
Victoria
Smarlyn
Abdullah
Maridania
Keny
Junior
Daze
Sarmad
Chris
Humayra
Kagbe
Yanvier
Abdullah
Besare
Kaylin
Responsibility Teams Section 1
Team 1
Team 2
Team 3
Team 4
Team 5
Thanya
Megany
Sandeilis
Alimatou
Sharna
Caroline
Katerina
Zoha
Henood
Maisha
Gabriela
Kimberly
Khady
Daiana
Sadia
Nathi
Obniel
Misha
Keyzie
Antoneta
Reyson
Robert
Harold
Scarlet
Marbelin
Responsibility Teams Section 2
Team 1
Team 2
Team 3
Team 4
Team 5
Team 6
Smaryln
Ramzi
Dajana
Jennifer
Chris
Junior
Mikauly
Geovani
Anam
Daze
Victoria
Sarmad
Maridania
Abdullah N.
Perla
Besare
Kagbe
Abdullah Z.
Laura
Ibrahim
Blendi
Yanvier
Kaylin
Jubayer
Mosammat
Seme
Humayra A.
Francisco
Humayera Z.
Sumaiya