Domain: EukaryaKingdom: Animalia Phylum: Chordata Dinosaurs1. Who were the dinosaurs?-Over 2 dozen genera (Feathered Dinosaurs)-Range in size: Chicken -> Blue Whale-Smallest: Fruitadens (Found in Colorado) -2 ft long?-Largest: Brachiosaurus (50 ft tall, 85 ft long “from snout to tail”)**Not all dinosaur fossils are bones. Preservation of soft tissue (RBC’s).2. Were they warm-blooded?a. Homeotherms vs Pilkilotherms (Temperature and Metabolism)b. Evidence from bone structure -Contain haversian canals (widely spaced growth rings)-Cold blooded reptiles have few canals closely packed growth rings-Dinosaurs have mammalian patternsc. Evidence from Predator/Prey Ratios-Homeotherms eat 10x more calories than poikilotherms- Mammals (Africa) – 1%; Reptiles – 20%d. Evidence from Locomotion-Dinosaurs walked like birds & mammals (anatomy & footprints) ***Some dinosaurs were probably homeothermic!3. What is their relation to birds?1. Many 2-legged walker2. Bird-type ankle joint3. Great expansion of hip bone4. Hindfoot arranged like birds5. Holes in the backbone for air sacs6. Pubic bone turned backward7. Brooding behavior is similar (Protection of young in nests)8. Feathers in dinosaursFeathers EvolutionFeathers evolved before flightTheir function:-Sexual Selection & Courtship-Insulation-Running (Increase speed)4. Social behavior of dinosaurs?Hypsilophodontis-Dinosaurs bred in colonies-Mothers arranged eggs-Young stayed in age-groupsHadrosaurs-Nests in colonies-Young born helpless must be parental care-Very fast growth-Footprints indicate herdsWhat would have happened if the dinosaurs had not become extinct?1. The mammals probably would not have had explosive adaptive radiation. And the reptiles might still rule the world.2. Maybe there would even be bipedal dinosaurs with grasping front limbs and pets as faithful
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