DINOSAUR FINALEvolution- The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.Natural Selection- The process where by organism better adapted to their environment tends to survive and produce off spring. Charles Darwin. (fitness= reproductive success) ERA PeriodDinosauria- The concestor of Iguanodon and Megalosaurus and all of its decendants.Food Chain: producers (usually plants) 1st order consumers 2nd order consumers apex preditor (highest on food chain)Fossil- The physical trace of life’s past.- Trace Fossils- record of organisms behavior- Body Fossils- record of an organisms physical structureTaphonomy- The study of burial and fossilizationModes of Preservation:CenozoicCretaceousMesozoicJurassicTriassicPaleozoic DescriptionSedimentary rocks are deposited into flat layers. Bottom= oldest, progressively younger as you go up.A structure that deforms rock must be younger than the deformed rock.Single, non-repeating, sequence of appearance of species through time.Principal of Stratigraphy1. Original Horizontality2. Superposition3. Cross Cutting Relations4. Fossil Succession- Unaltered Bone= original hard parts are still present with nothing added. This is rare- Permineralized= common, hard part remains but new material is added, kind of like cement.- Recrystallization= after burial, crystals reorder and grow into each other, mineralogy remains but structure is lost- Replacement= partial/complete replacement of crystals of one mineralogy withanother- Carbonization= organic material is distilled under pressure, material is lost but carbon film is intact, preserves soft tissue.- Impressions= as if the body was pressed into mud and hardenedBone Wars- Marsh and Cope- Helped find more fossils and increased our knowledge of evolutionary trendsEvolutionary TrendsCorrelatedProgression Divergence ConvergenceVariation- Sexual Dismorphism= different sexes have different traits- Ontogenetic= babies look different than adults- Geographic= populations in different regions have different traits- Stratigraphy= ancestors may shift in some traits- Individual= no two individuals in a population are identicalTriassi-Jurrasic Extinction:-Wiped out: - Non-dinosauromorphs- Pseudosuchains other than ancestors of crocodilians- Therapsids other than ancestors of mammals-Therefore only leaving DinosaursFour methods to infer dinosaur biology:- Analogies to modern animals- Development and diversification distribution of traits in current animals should be present in dinosaurs- Biomechanics- The sedimentological and trace fossil recordIsometry- the growth of body part increase directly in proportion to increase in total mass.Negative Allometry- body part grows proportionally slower than over size increase.Positive Allometry- body part grow proportionall faster than overall size increase.Behaviors:- Displays= various “messgaes”- Sexual Displays: to attrack mates-Territorial Displays: defend territory- Defensive Displays: to warn off potential threats- Specific Recognition: features distinction to each species- Combat- Locomotion: adaptions for weight baring vs speed- Feeding: carnivore and herbivorousIntraspecific- within a speciesInterspecific- between speciesSexual Dismorphism- when the two sexes have distinct formsOntogenetic Changes- some differences between males and females are presentat birth.Birds:Paternal care- males watch over the nestGround Nesting- nested on the groundPrecocial- Able to more around easily shortly after birthAltricial- Nest bound, wholly dependent on parents for foodLines of Arrested Growth (LAGS)- growth rings, one per year, when the lines get loser together the dinosaur has stopped growingSkeletochronology- Used to determine chronology of age“r” Selected:- Have lost of babies- Don’t invest a lot of time in one baby- Chance of survival is small- Short life span“K” Selected- Only a few babies- Invest a lot of time in their babies- Chanced of survival are much better- Tend to have longer life spansHow and why did dinosaurs get so large?- Short food chains (usually only three steps) therefore they receive more of the energy and nutrients- Change in atmosphere higher oxygen levels and therefore making it easier to power such high metabolismsEnergy Source Metabolic Rate(energy used)TermperaturesWarm Blooded- Comes from inside the cells - Turns foodinto energy to heat (endotherm)- Rate of fuel use is high- Tachymetabolic= fast metabolism- Body temperature regulated by internal mechanisms (homeotherm)Cold Blooded- Main energy sourceis the sun (ectotherm)- Rate of fuel use is slow- Bradymetabolic= slow metabolism- Body temperature fluctuates with external environment (poikliotherm)Warm Blooded= endotherm, tachymetabolic, homeothermCold Blooded= ectotherm, bradymetabolic, poikliothermWhy do we think dinosaurs are warm blooded?- Upright positiono Problem- no relationship ever established- Origins of birds: they were warm bloodedo Problem- people believe earlier birds were ectothermic (cold blooded)- Growth Rate: great rate suggested tachymetabolico Problem: known ectotherms have good growth rates alsoWhy do we think Dinosaurs are cold blooded?- Small Brain Sizeo Problem: no link between brain size and endothermy- Overheating: Dinosaurs would overheat if they were warm bloodedo Problem: some animals can dump excess heat- Growth Lineso Problem: no connection to bloodWhat they actually are: Warm BloodedWhy? In order for huge dinosaurs to run they must have high metabolic rates and therefore they must be tachymetabolic- Aerobic Respiration (glucose + oxygen  water + energy)- Anerobic Respiration (food  lactic acid +energy)Mass extinction- geologically rapid extinction of many distantly related taxa which are not immediately replaced in ecological space.-Usually what causes a new eraThe end of the Mesozoic Era is the boundary between the Cretaceous period (K) and the Paleogene period (Pg);- Therefore this boundary is called K/Pg- Not the largest extinction but the most recent one that was really largeWho died out?- Coccolithophorids: nannoplankton algae- Common in Cretaceous- Survived but at much reduced numbers- Base of the food chain- Ammonoids: shelled, relative of squids- Common in the Mesozoic- Food for many reptiles- Were extinct*But there were a lot of survivorsWhy did this extinction occur?- Old predictions:-Poison gas from comets-