Dino
Scienc
Mike Kozina
SASS
July 18, 2012
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What is a dinosaur?
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That’s right—birds are now dinosaurs!
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Types of Dinosaurs
Saurischia: Lizard-Hipped
Ornithischia: Bird-Hipped
Thyreophorans
Sauropods
Theropods
Ornithopods
NBA Players
Marginocephalia
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Dino Sizes
Name
Height
Length
Weight
Ankylosaurus (armored lizard) 7 ft. 2.1 m 35 ft. 10.6 m 10,000lbs 4,536kg.
Apatosaurus (deceptive lizard) 15 ft. 4.5 m 75 ft. 22.9 m 66,000lbs 29,937kg.
Argentinosaurus (Argentina lizard) 70 ft. 21.4 m 120 ft. 36.6 m 220,000lbs 99,792kg
Brachiosaurus (arm lizard) 50 ft. 15.2 m 100 ft. 30.5 m 100,000lbs 45,360kg
Compsognathus (elegant jaw) 2 ft. 0.6 m 3 ft. 0.9 m 8lbs 3.6kg
Corythosaurus (helmet lizard) 16 ft. 4.9 m 30 ft. 9.1 m 8,860lbs 4,019kg
Deinonychus (terrible claw) 5 ft. 1.5 m 9 ft. 2.7 m 175lbs 80kg
Iguanodon (iguana tooth) 18 ft. 5.5 m 30 ft. 9.1 m 10,000lbs 4,536kg
Seismosaurus (tremor lizard) 84 ft. 25.6 m 150 ft. 45.7 m 200,000lbs 90,720kg
Stegosaurus (plated lizard) 11 ft. 3.4 m 30 ft. 9.1 m 6,000lbs 2,722kg
Triceratops (three-horned face) 9.5 ft. 2.9 m 26 ft. 7.9 m 14,000lbs 6,350kg
Tyrannosaurus (tyrant lizard) 23 ft. 7.0 m 50 ft. 15.2 m 14,000lbs .6,350kg
Velociraptor (swift robber) 2 ft. 0.6 m 6 ft. 1.8 m 250lbs .113kg
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Dino Sizes
Name
Height
Length
Weight
Ankylosaurus (armored lizard) 7 ft. 2.1 m 35 ft. 10.6 m 10,000lbs 4,536kg.
Apatosaurus (deceptive lizard) 15 ft. 4.5 m 75 ft. 22.9 m 66,000lbs 29,937kg.
Argentinosaurus (Argentina lizard) 70 ft. 21.4 m 120 ft. 36.6 m 220,000lbs 99,792kg
Brachiosaurus (arm lizard) 50 ft. 15.2 m 100 ft. 30.5 m 100,000lbs 45,360kg
Compsognathus (elegant jaw) 2 ft. 0.6 m 3 ft. 0.9 m 8lbs 3.6kg
Corythosaurus (helmet lizard) 16 ft. 4.9 m 30 ft. 9.1 m 8,860lbs 4,019kg
Deinonychus (terrible claw) 5 ft. 1.5 m 9 ft. 2.7 m 175lbs 80kg
Iguanodon (iguana tooth) 18 ft. 5.5 m 30 ft. 9.1 m 10,000lbs 4,536kg
Seismosaurus (tremor lizard) 84 ft. 25.6 m 150 ft. 45.7 m 200,000lbs 90,720kg
Stegosaurus (plated lizard) 11 ft. 3.4 m 30 ft. 9.1 m 6,000lbs 2,722kg
Triceratops (three-horned face) 9.5 ft. 2.9 m 26 ft. 7.9 m 14,000lbs 6,350kg
Tyrannosaurus (tyrant lizard) 23 ft. 7.0 m 50 ft. 15.2 m 14,000lbs .6,350kg
Velociraptor (swift robber) 2 ft. 0.6 m 6 ft. 1.8 m 250lbs .113kg
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When did Dinosaurs rule the earth?
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Dinosaur Motion/Mechanics
• How fast did dinosaurs go?
• How could they support
such large bodies?
• Did land dinosaurs swim?
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Similarity
• Simple scaling does not necessarily reproduce
the same results
E.g.: Animal mass ~ bone volume; Bone strength ~ bone cross
section  can’t just scale up
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So, how can we relate big to small?
Unitless ratio of relevant physical parameters:
1. g = acceleration from gravity
2. v = velocity
3. L = linear length scale
Froude Number (centripetal force/gravitational force):
𝑣2
𝐹=
𝑔𝐿
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Other similarity terms you may have heard
• Reynold’s number (inertial forces/viscous
𝜌𝑣𝐿
forces) 𝑅 =
𝜂
• Strouhal number (oscillation
𝑣𝜏
time/characteristic translation time) 𝑆 =
𝐿
• Prandtl number (viscous diffusion rate /
thermal diffusion rate) 𝑃 =
𝜂𝐶𝑝
𝑘
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How fast could they run, and how do we know?
Estimate speed of dinosaurs using:
1. Stride length (from footprints)
2. Hip height
3. Froude number for modern day
mammals
So, how fast?
1. Sauropods ~ 1m/s
2. Fastest tracks (from horse-sized
biped) ~12m/s
Problems:
1. Even for mammals scaling fails
for small sizes because
movement pattern very
different
2. Footprints only tell velocity in
certain types of terrain (those
likely to have tracks saved)—not
representative
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Other ways to estimate velocity
• Relate bone strength to general athleticism
– E.g. Triceratops estimated to be in between
elephant and rhino in speed
• Computer simulations:
– Genetic algorithms search to extremize
parameters such as energy consumption or speed
– Some require knowing motion patterns
Can use constraints to eliminate impossible
orientations
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Some simulation results
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Size Problems: How could Littlefoot
grow so big?
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What about blood flow?
• Open question
• Extremely robust hearts?
• Possibility that long necks never raised above
~30degrees?
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Did dinosaurs
swim?
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Why did they die out?
•
•
•
•
•
•
Hormonal problems leading to thin eggshells
Volcanos put dust in the air blocking the sun
Over predation by carnosaurs
Slipped disks in vertebral column
Blindness from cataracts
Climate became
1.
2.
3.
4.
•
•
•
•
Too hot
Too cold
Too wet
Too dry
Constipation
Fluctuations in the gravitational constant, somehow affecting dinosaurs
Radiation from a supernova
Uranium poisoning
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Really, why did they
die out?
• Overwhelming evidence for asteroid
colliding with the earth
• Sharp break in fossil type—K/T boundary
• High levels of iridium in soil
• Large crater in Chixhulub, Mexico 65.5 MYA
• Estimate size of asteriod ~10km diameter
(since iridium at K/T found worldwide)
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More evidence for asteroid impact
• Shocked quartz
caused by impact
• Microtektites—bits
of glass ejected from
impact site
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Dino-related Research at SLAC
• Use synchrotron to pick out different chemicals left in
Archaeopteryx fossil
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• Can link chemicals to pigment density
Selected Bibliography
• Dinosaur Diversity
– Wang, PNAS 103 13601-13605 (2006)
• Dinosaur Biomechanics/Motion
– Sellers, Proc. R. Soc. B 274 2711-2716 (2007)
– Alexander, Scientific American, April 1991
– Alexander, Proc. R. Soc. B 273 1849-1855 (2006)
• Sauropod Size Issues
– Seymour, Biol. Lett. 5 317-319 (2009)
– Sander, Science 322 200-201 (2008)
– Henderson Proc. R. Soc. Lond. B (Suppl.) 271 S180-S183 (2004)
• General Dino Stuff (includes all info I used about extinction)
– Fastovsky, D. and Weishampel, D. Dinosaurs: A Concise Natural History.
Cambridge University Press (2009)
• Dino research at SLAC
– Bergmann, PNAS 107 9060-9065 (2010)
• Similarity in other contexts (non-dino)
– Landau, L.D. and Lifshitz, E.M. Fluid Mechanics: Course of Theoretical Physics
Vol. 6. 2nd Ed. Butterworth-Heinemann (2010)
– http://en.wikipedia.org/wiki/Dimensionless_number
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Thanks for listening!
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