Mike Kozina - PowerPoint Presentation

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Mike KozinaSASS July 18, 2012

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Dino ScienceSlide2

What is a dinosaur?2Slide3

That’s right—birds are now dinosaurs!3Slide4

Types of Dinosaurs4

Sauropods

Theropods

Marginocephalia

Saurischia: Lizard-Hipped

Ornithischia

: Bird-Hipped

NBA Players

Thyreophorans

OrnithopodsSlide5

Dino Sizes5

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 3.6kgCorythosaurus (helmet lizard) 16 ft. 4.9 m 30 ft. 9.1 m 8,860lbs 4,019kgDeinonychus (terrible claw) 5 ft. 1.5 m 9 ft. 2.7 m 175lbs 80kgIguanodon (iguana tooth) 18 ft. 5.5 m 30 ft. 9.1 m 10,000lbs 4,536kgSeismosaurus (tremor lizard) 84 ft. 25.6 m 150 ft. 45.7 m 200,000lbs 90,720kgStegosaurus (plated lizard) 11 ft. 3.4 m 30 ft. 9.1 m 6,000lbs 2,722kgTriceratops (three-horned face) 9.5 ft. 2.9 m 26 ft. 7.9 m 14,000lbs 6,350kgTyrannosaurus (tyrant lizard) 23 ft. 7.0 m 50 ft. 15.2 m 14,000lbs .6,350kgVelociraptor (swift robber) 2 ft. 0.6 m 6 ft. 1.8 m 250lbs .113kgSlide6

Dino Sizes6

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 3.6kgCorythosaurus (helmet lizard) 16 ft. 4.9 m 30 ft. 9.1 m 8,860lbs 4,019kgDeinonychus (terrible claw) 5 ft. 1.5 m 9 ft. 2.7 m 175lbs 80kgIguanodon (iguana tooth) 18 ft. 5.5 m 30 ft. 9.1 m 10,000lbs 4,536kgSeismosaurus (tremor lizard) 84 ft. 25.6 m 150 ft. 45.7 m 200,000lbs 90,720kgStegosaurus (plated lizard) 11 ft. 3.4 m 30 ft. 9.1 m 6,000lbs 2,722kgTriceratops (three-horned face) 9.5 ft. 2.9 m 26 ft. 7.9 m 14,000lbs 6,350kgTyrannosaurus (tyrant lizard) 23 ft. 7.0 m 50 ft. 15.2 m 14,000lbs .6,350kgVelociraptor (swift robber) 2 ft. 0.6 m 6 ft. 1.8 m 250lbs .113kgSlide7

When did Dinosaurs rule the earth?7Slide8

Dinosaur Motion/MechanicsHow fast did dinosaurs go?

How could they support such large bodies?Did land dinosaurs swim?

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SimilaritySimple scaling does not necessarily reproduce the same results

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E.g.: Animal mass ~ bone volume; Bone strength ~ bone cross section

 can’t just scale upSlide10

So, how can we relate big to small?

Unitless ratio of relevant physical parameters:g = acceleration from gravity

v = velocityL

= linear length scaleFroude Number (centripetal force/gravitational force):

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Other similarity terms you may have heard

Reynold’s number (inertial forces/viscous forces)

Strouhal

number (oscillation time/characteristic translation time)

Prandtl

number

(viscous diffusion rate / thermal diffusion rate)

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Estimate speed of dinosaurs using:

Stride length (from footprints)

Hip height

Froude number for modern day mammalsSo, how fast?Sauropods ~ 1m/s

Fastest tracks (from horse-sized biped) ~12m/s

Problems:

Even for mammals scaling fails for small sizes because movement pattern very different

Footprints only tell velocity in certain types of terrain (those likely to have tracks saved)—not representative

How fast could they run, and how do we know?Slide13

Other ways to estimate velocityRelate bone strength to general athleticismE.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 orientations13Slide14

Some simulation results14Slide15

Size Problems: How could Littlefoot grow so big?

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What about blood flow?Open questionExtremely robust hearts?

Possibility that long necks never raised above ~30degrees?

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Did dinosaurs swim?17Slide18

Why did they die out?Hormonal problems leading to thin eggshellsVolcanos put dust in the air blocking the sun

Over predation by carnosaursSlipped disks in vertebral column

Blindness from cataractsClimate became

Too hotToo coldToo wetToo dryConstipationFluctuations in the gravitational constant, somehow affecting dinosaurs

Radiation from a supernovaUranium poisoning18Slide19

Really, why did they die out?

Overwhelming evidence for asteroid colliding with the earthSharp break in fossil type—K/T boundaryHigh levels of iridium in soilLarge crater in

Chixhulub, Mexico 65.5 MYAEstimate size of

asteriod ~10km diameter (since iridium at K/T found worldwide)19Slide20

More evidence for asteroid impactShocked quartz caused by impact

Microtektites—bits of glass ejected from impact site

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Dino-related Research at SLACUse synchrotron to pick out different chemicals left in Archaeopteryx fossil

Can link chemicals to pigment density

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Selected BibliographyDinosaur DiversityWang,

PNAS 103 13601-13605 (2006)

Dinosaur Biomechanics/MotionSellers, Proc. R. Soc. B

274 2711-2716 (2007)Alexander, Scientific American, April 1991Alexander, Proc. R. Soc. B 273 1849-1855 (2006)

Sauropod Size IssuesSeymour, 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 SLACBergmann, 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_number22Slide23

23Thanks for listening!