Dinosaurs

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Dinosaurs

• From Your Questions

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Dinosaur Distribution

• Where are they found?
• United States, Argentina, Mongolia, China,
  Central Asia, Africa, Antarctica, etc.
• Did dinosaurs live in NY? If so, which ones?
• Footprints of Coelophysis

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Dinosaur Distribution

• What environments did they inhabit?
• River Valleys, plains, coastal lowlands, etc.
• Did they live in cool climates?
• Probably, but still under investigation

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Dinosaur Distribution

• How abundant were they?
• Probably at least as abundant as Mammals are now.
• Some indications of large herds of hundreds of
  individuals
• What were the relative abundances of terrestrial
  and aquatic forms?
• Majority were terrestrial

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Dinosaur Systematics Biostratigraphy

• What is the oldest dinosaur known?
• Triassic
• From what are they descended?
• Early stem reptiles
• To what are they related?
• Reptiles and probably birds
• How many species have been found?
• Hundreds, and counting!
• How long were they around?
• Approximately 180 Ma!

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• What caused their extinction?
• Multiple hypotheses
• Bolide impact
• Volcanism
• Climate change
• All of the above
• Do they have any living descendents?
• Maybe!

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Is There a Dinosaur in Your Backyard?
Confusciornis
Archaeopteryx
Early Baby Bird 135 Ma
Caudiopteryx
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Solnhofen Lagerstatten

• Jurassic Solnhofen Limestone
• Soft tissues
• Archaeopteryx
• Hypersaline lagoon with very fine micrites

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Paleobiology of Dinosaurs

• Why were they so large?
• Why not?
• Were they warm or cold blooded?
• Strong evidence favors warm-blooded
• Trackways speed
• Haversian canals in bones
• Skeletal morphology active habits
• Affiliation with birds

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Paleobiology of Dinosaurs

• What do we know about their diet and how do we
  know it?
• Herbivores and carnivores
• Distinction made on dentition, skeletal
  structure, gastroliths
• Tooth morphology clues to diet
• Coprolites direct evidence
• Morrison Formation a dinosaur lagerstatte
• What do we know about their internal systems?
• Rare instances of preservation Italian Alps
  specimen
• Was Tyrannosaurus rex a predator or scavenger?

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Paleobiology of Dinosaurs

• Has any soft tissue been found?
• Have any babies ever been found in eggs?

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Paleobiology of Dinosaurs

• Has any soft tissue been found?
• Have any babies ever been found in eggs?

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Miscellaneous and/or Unanswerable Questions

• What was their average life span?
• How intelligent were they?
• Did they have night vision?
• How did they interact with early mammals?
• If they were around now, would they eat people?
• Can they be cloned/grown (as in Jurassic Park)?

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Reptiles and Mammals

• Reptile Adaptive Radiation included
• Dinosaurs
• Therapsids mammal-like reptiles
• Therapsids gave rise to mammals

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What does it mean to be a mammal?

• Characteristics of mammals?

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Early Mammals

• Small, rodent-like creatures
• Possibly nocturnal
• Some lines became extinct in Cretaceous
• Late Cretaceous to Early Cenozoic Adaptive
  Radiation

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Major Groups of Extant Mammals

• Placentals
• Marsupials
• Monotremes
• Edentates