Transcript GEOLOGY MACC Bill Palmer

GEOLOGY
MACC
Bill Palmer
Lecture 9
Vertebrate Fossils
GEOLOGY
 Jawless
 1-2
Vertebrates
inches long
 Look like tadpoles
 Large head shield with armor plating
 Gills used for feeding and breathing
 Would suck mud and gills filter out any food
 Devonian –400 mya
GEOLOGY
Athenaegis-a jawless fish
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 Jawed
 Fish
Fish
developed jaws..can kill and eat stuff
 Placoderms are earliest of jawed fish
 Have no teeth-cutting edges-like a turtle-vicious
 Big-30 ft.!
 Placoderms died out but relatives are with us todaysharks and rays
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Placoderms-first jawed fish
GEOLOGY
 Bony
Fish
 Much
 Scales
like today
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Bony fish fossils
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 Lobe-finned
 Fins
fish
have sturdy bony structure
 Crossopterygians 300 mya
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Crossopterygian on
Canadian stamp
COELECANTH-a living
crossopterygian
GEOLOGY
Diagrams showing how lobed
fins could lead to legs.
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 Primitive
 Simple
amphibians
amphibians difficult transition as hard to
support body on land
 Developed ability to hear
 Few fossils-acid swamp water destroys flesh
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Ichthyostega-primitive
amphibian-lived in
water and crawled on
the bottom. 5 ft long,
7 toes on each foot
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Eusthenopteronanother primitive
amphibian- could
leave water. 5 ft
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 Dinosaurs-”Terrible
 Big,
reptiles”
fierce, and dead
 Appeared 140 mya and then disappeared 65 mya
 Scales or skin with bony knobs
 Small brains
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Supersaurus
 130 feet long
 Longest but not heaviest dinosaur
 Discovered in 1972 in Colorado
 Weighed 100,000 lbs
 Lived 150 mya
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Supersaurus-What
could the long tail be
used for?
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 Apatosaurus
 Was
known as Brontosaurus
 140 mya
 50,000 lbs
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Apatosaurus
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Stegosaurus
 “Roof-lizard”
 Tail with spikes
 150 mya
 30 ft long
 14 ft tall
 10,000 lbs
 Brain=2.8 oz

GEOLOGY
Triceratops
 65 mya
 3-horned face
 No Complete skeleton has
ever been found!
 26 feet long
 7 ft tall
 13,400 lbs

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GEOLOGY
Tyrannosaurus
 “Tyrant Lizard”
 43 ft long
 68-65 mya
 15,000 lbs

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 The
great Die-Off-Mass Extinction
 Five events in last 5 billion years
 Why did the dinosaurs disappear? Some theories:
GEOLOGY
Why did the dinosaurs disappear? Some theories:
1. Global Climate Change
Earth temperature varies. Did a cooling of the earth's
temperature cause dinosaurs to disappear?
If animals cannot adapt or move to a suitable climate,
they will die.
GEOLOGY
Why did the dinosaurs disappear? Some theories:
2. Tectonic Activity
Tectonic activity causes mountain building,
movement of the earth’s crust, and changes in the
amount of sea.
If animals can not adapt thy will die off.
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Why did the dinosaurs disappear? Some theories:
3. Asteroid or Comet Impact
Impact of asteroid or comet would send so much dust
and debris into the atmosphere that it could blot out
the sun and cause darkness and cold.
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Why did the dinosaurs disappear? Some theories:
4. The appearance of a predator or competitor.
It is believed that some animals have become extinct
because a more efficient competitor out competed
them.
Could mammals have out competed dinosaurs?
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 Why
did the dinosaurs disappear?
 What
do I think?
 A meteor plunged the eath into cold and dark.
 Why
do I think this?
 Crater
in Yucatan
 Iridium Layer
GEOLOGY
 Why
did the dinosaurs disappear?
 What
do I think?
 A meteor plunged the earth into cold and dark.
 Why
do I think this?
 Crater
in Yucatan
 Iridium Layer
GEOLOGY
A large crater exists in
the Gulf of Mexico.
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A thin Iridium
Layer is found
around the
world.
This layer
corresponds to
the time the
dinosaurs
became extinct.
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 Mammals-American
 Largest
Lion
Lion to ever exist
 25% larger than African Lion
 12 feet in length
 5-600 lbs
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Mastodon
 Ate twigs-Browser
 Extinct 10,000 ya
 Bigger head than
mammoth
 Tusk=15 ft.
 Food for early humans
 Teeth like “mast” (breast)

Mammoth
 Ate grass-grazer
 4.8 mya-4,000 ya
 Originated in Africa
 16 ft tall at shoulder

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mammoth
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mastodon
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Mastodon State Park
GEOLOGY-Wrap-ups
1.
2.
3.
4.
5.
What is Athenaegis?
What are Placoderms?
What is a Coelacanth?
What are the characteristics of Ichthyostega?
What is the largest dinosaur?
GEOLOGY-Wrap-ups
6. What is a Stegosaurus? Characteristics?
7. Summarize four theories why the dinosaurs
became extinct.
8. What are the differences between a mastodon and
an mammoth?
9. What is Iridium?
10. What use was a long tail in Supersaurus?