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PALEO 200! LESSON 1 ANATOMY Paleontology study of prehistoric life Fossil preserved evidence of a prehistoric organism (bones, footprints, eggshells, poop, skin, feathers) birds are the smallest of the dinosaurs Adaptations traits that have evolved to serve specific functions Bones: resist gravity a...

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PALEO 200! LESSON 1 - ANATOMY Paleontology - study of prehistoric life Fossil - preserved evidence of a prehistoric organism (bones, footprints, eggshells, poop, skin, feathers) - birds are the smallest of the dinosaurs Adaptations - traits that have evolved to serve specific functions Bones: - resist gravity and keep form - provide framework for muscles - provide protection - store mineral reserves (calcium) Vertebrates are defined by a skull and vertebrae (bone/cartilage structure surrounding spinal cord) ex: fish, amphibians, turtles, snakes, birds, mammals - the first vertebrates were aquatic animals (500 million ya) Invertebrates don’t posses vertebrae (insects, spiders, snails, clams, jellyfish, worms) Brain Case - skull chamber that houses the brain with opening for nerves (size = mental capacity) - Jaw size as well as teeth or a beak tell us what they ate Nares = nostrils Orbits = eyes Fenestrae = additional openings: - Laterotemporal = sides - Supratemporal = top - Antorbital = reduced weight of skull or large sinus cavities? -Vertebral Column comprised of a centrum (spool/disk), neural arch, and neural canal (housing spinal nerves) - Transverse (lateral) and spinuous (top) processes exist for muscle attachment and articulation surfaces

- Cervical vertebrae = neck - Dorsal Vertebrae = back (all connect to ribs) - Sacral Vertebrae = hips - fused with each other as well as pelvic bones to form SACRUM - Caudal Vertebrae = tail...chevrons - Gastralia = belly ribs - Tetrapods = 4 feet Limb Girdles: Pectoral - forelimbs connect Scapula = shoulder blade Pelvic = hindlimbs connect (ilium = upper hip, pubis = belly, ischium - tail Acetabulum - joint hole for articulation

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- Humerus: largest arm bone which connects to the radius (thinner) and ulna - Carpels: wrist bones connecting metacarpels and phalanges (fingers) - Femur: largest leg bone which connects to the fibula (thinner) and tibia - Tarsals: ankle bones connecting metatarsels and phalanges - When dinos walked, only their toes touched the ground (allowing for longer steps)

2 types of Dinosaurs with respect to the skeleton: SAURISCHIAN - pubis extending down and forward ORNITHISCHIAN - beak bone in upper jaw (predentary) and a pubis extending down and back (allowed more space in the ribcage) Saurischians were comprised of 2 groups: Sauropodomorphs - large herbivores with long necks and small heads Prosauropods/Sauropods - largest animals to ever walk the earth...vertebrae with air sacs and simple peg-like teeth Ornithischians - primarily herbivores - possessed beaks - pubis point BACKWARDS 5 major groups: • Ornithopods: lacked armor, bipedal, antelope sized > Iguanodonts: large ornithopod with spike-shaped claw > Hadrosaurs: duckbills, tightly packed small teeth • Pachycephalosaurs: bipedal, short arms, strong tail, armored skulls, potential omnivore • Ceratopsians: parrot-like beak and expanded rear skull, large horns • Stegosaurs: quadrupedal, osteoderm spikes [develop within the skin], front limbs shorter than back, narrow snout • Ankylosaurs: heavily armored, quadrupedal, wide rib cage, tail club Integument - body covering Keratin - tough flexible material that composes hair, fingernails, claws, beaks, horns Melanosomes - pigment cells within feathers

LESSON 2 - DEATH/FOSSILIZATION TAPHONOMY - the study of all natural processes that involve an organism after it dies (how it decays, is scavenged, becomes fossilized, erodes) - Bloat-and float: a decaying body swells with gases and can float away - finding complete dinosaurs is rare Factors contributing to disarticulation: • partial consumption • swept away by rivers/flood • exposure to sunlight • trampled • mineral leach by roots of plants - Plastic deformation: pressure causes fossil shape to change - to become fossilized a bone must be buried, most of the time by water washing sand/ mud over it (therefore more common in wet environments and low elevation) - Fluvial Deposits: river/stream deposits - Lacustrine deposits: lake deposits which preserve soft tissue better due to finer sediment - Aeolian deposits: wind - Sedimentary rocks: mineral and organic material accumulate and cement together - Igneous rocks: cooled and hardened lava - metamorphic rocks: the other two changed by heat or pressure - Mudstone/Shale: rocks formed from mud/silt (lake bottom) - Sandstone: rocks formed from sand (beach, ocean floor) - Coal: forms from compressed remains of plants (swamp) - Limestone: accumulation of shells/exoskeletons (shallow marine environment) - Preservation styles: different ways fossils form... • perimineralization - empty internal spaces of bone fill with minerals • replacement - original bone decays and minerals occupy the space - Badlands: places where vegetation is sparse, erosion rates high and large amounts of sedimentary rock exist

- Overburden: rock/earth that covers a fossil - Orientation - long bones may be aligned in the same direction, revealing they were transported by water moving in a specific direction - Tooth marks - indicate scavenging/feeding LESSON 3 - EATING - dino evolution spans 160 million years - fossil gut contents are rare, so palaeontologists must compare feeding adaptations to existing modern animals to hypothesize about dino diet - Herbivores: thin, ridgid leaf-shaped teeth for grinding - Carnivores: sharp teeth for piercing, claws for holding prey, serrated teeth - Frugivore: eat primarily fruit - Piscivore: eat primarily fish; tall, sharp, conical teeth good for spearing and long jaws capable of snapping shut - Insectivores: specialized carnivores that eat primarily insects (piercing teeth to puncture chitin, or weak jaws with reduced teeth -> swallow insects whole) • insectivores usually have spade like claws for digging and short, powerful limbs - Durography: rounded teeth and powerful jaws to crack bones > allows for access to bone nutrients - Omnivores: eat meat and plants - unspecialized or variety of teeth - Dinosaurs grew new teeth throughout their lives > when an old tooth was ready to be replaced, its root would be reabsorbed and the old crown eventually shed - the presence of predator teeth around a skeleton may not tell us about predation but rather just scavenging/feeding Plant cells are composed of cellulose, which is hard to digest - bacteria and chewing aid in digestion - dental batteries: densely packed teeth that form a single chewing surface * Hadrosaurs and ceratopsians developed batteries - teeth were replaced rapidly as there were over 1000 - teeth surface was not uniform due to grinding

Batteries in hadrosaurs and ceratopsians evolved independently: Hadrosaurs - chewing surface angled downwards but horizontal - chewed in every direction - inset teeth, large cheeks Ceratopsians - vertical surface - chewed like scissors - inset teeth - hadrosaurs and sauropods had simple teeth for nipping vegetation, but made up for digestion with huge ribcages that housed immense internal organs - oviraptosaurs and ornithomimids had gastroliths (ribcage stones) which were part of gastric mills prior to the stomach (still seen in chickens) OR used for buoyancy Dromaeosaurs - had thin tails with rod-like projections (velociraptor), serrated bladelike teeth and sickle shaped claws (slash, puncture, climb trees) > Microraptor Spinosaurs - skulls resemble crocodiles and thought to be piscivores Alvarezsaurs - small theropods with short limbs and compact hands; insectivores Tyrannosaurs - evolved late with reduced front limbs and robust skulls, serrated teeth, noticeable attachment sites for jaw muscles (tremendous biting force) Scavenging - consumption of an already dead animal Cololites: fossil gut contents Sinocalliopteryx - fed on birds and small dinos Coprolites: fossil poop - tyrannosaurs could not digest bone

LESSON 4 - MOVING AROUND Sprawling Stance (lizards, turtles, crocodiles, salamanders) - humerus and femur project horizontally, with elbows and knees strongly bent Erect Stance (birds, mammals) - humerus and femur project vertically, limbs pointing straight down from their girdles An erect stance has a number of advantages: • limbs directly under the body, allowing limb bones to passively support the animal’s weight • allows limb bones to contribute to the length of a stride, improving speed and agility - all modern tetrapods share an ancestor that had a sprawling stance - postures are easy to identify based on limb joints and articulation of girdles - Dinosaurs stood erect Cursorial limbs - adapted for fast locomotion, elongated, very long lower leg bones - cursorial animals stood on their toes (digitigrade posture - cheetahs/ostriches) or toenails (unguligrade - horses/antelopes) - Humans have plantigrade posture (stand on heels) and their phalanges and metatarsals contact the ground Ornithomimids have digitigrade stance and long metatarsals Graviportal limbs - adapted for supporting extreme body weight - bones robust and heavy - large feet with fleshy pads (absorb impact) - short limbs, joints bend minimally (elephants) Obligate Bipeds - almost always walk or run on 2 legs Obligate Quadrupeds - almost always walk on 4 legs

Facultative Bipeds - walk on 4 but rise on two to run (primates, kangaroos, lizards) - The ancestor of dinosaurs was an obligate biped

Obligate Biped - prosauropods (could have been obligate or facultative) - small certopsians - small ornithopods

Quadruped - Sauropods - stegosaurs - ankylosaurs - large ceratopsians

Facultative Biped - small ceratopsians - hadrosaurs - iguanodonts

- most dinosaurs were adapted to carrying most of their weight on their hind legs and could probably at least stand on two legs - Caudofemoralis: muscle that pulls backwards on the hind leg, important for power when running...anchored to the ilium, caudal vertebrae, chevrons and femur - Trochanter: prominence of bone on the femur of birds and crocs where the caudofemoralis attaches - some dinos had a large caudofemoralis, indicating they had great hindlimb power and were strong runners - On theropods, trochanter is high = fast sprinting (muscle retracts quickly) - On hadrosaurs, trochanter is low = slow, better muscular endurance (grazing) Ichnofossils - fossils that record traces of biologic activity (fossils, footprints, toothmarks) - footprints provide evidence for dinosaur posture and locomotion - Trackways: series of dino footprints made in mud (tell us how fast dinos moved) - most bipedal dinos held their body horizontally with their tail off the ground - iguanodonts and hadrosaurs left deep imprints with their hind feet and shallow tracks made by front feet

- dinosaurs were likely warm-blooded - ENDOtherm = warm blooded > regulate body temp through metabolic processes (sweating, panting, shivering) ... must expend and consume large amounts of energy • endos can survive very cold climates and can maintain high activity levels (don’t need to stop frequently) - ECTOtherm = cold blooded > internal temperature depends on external temp (most animals) - limbs and bones support the conclusion that dinos were endotherms - Histology: slicing bones into thin cross sections - Osteons: bone cells > osteons of dinos arranged like modern endos - dinosaurs could have been gigantothermic?? (low ratio of SA to V prevented them from losing heat to external world)

LESSON 5 - BIRTH, GROWTH, AND REPRODUCTION - 312 MYA (before dinos were around) the amniotic egg evolved - Amniotic Egg: have encapsulating membranes that are watertight, hard leathery shells, and can be laid in dry areas - Amniotes: animals that lay amniotic eggs - most mammals don’t lay eggs, but the uterus is a similar structure in the embryo - eggs are not airtight > exchange of gases and waste limits egg size - largest egg from an Oviraptosaur - Lines of Arrested Growth (LAGS): rings inside bones created by temporarily hindered growth due to scarce seasonal periods - Tyrannosaurus Rex grew to adult size in 20 years, Sauropods in 30 (1-2 pounds/day!) - Young dino bones had high vascularity and lamellar bone texture - Remodeling: old bone cells replaced by new cells - Haversian: new, secondary bone - External Fundamental System (EFS): closely spaced LAGs indicating skeletal maturity - Ontogenetic Changes: occur as an organism matures (baby’s head is large at birth and throughout growth the proportions even out)

- Non-Isometric Ontogenetic Changes: changes in proportions as an animal grows (NOT FROM AN INCREASE IN SIZE) > horns/frills of ceratopsians, tibia and femur in tyrannosaurs - Isometric Changes: changes in size but NOT proportions > relative tibia to femur ratio in juvenile and adult ceratopsians - Sexual Dimorphism: males and females of the same species are different (sexually dimorphic features are generally ontogenetic) > some Protoceratops had wider frills, some Confuciusornis (ancient bird) had extra long tail feathers - Brooding/Incubating: sitting atop eggs - Medullary Bones: contain lots of Calcium for egg development (identifies females) - dinos have been fossilized while brooding and young/old dinos have been fossilized near each other, suggesting family living orientation - Predator Satiation: large amount of eggs laid at the same time and place by a group; only a fraction hatched and grew into adults > employed by sauropods and modern sea turtles LESSON 6 - ATTACK AND DEFENSE - Deterrents: horns, spikes, armor or other features on animals that discourage predators from attacking > horns of triceritops > anadontosaurus were covered in osteoderms and had a club tail > stegosaurus tail spikes - large size can be a defense on its own (Sauropods) - Cursorial Limbs helped some dinos outrun predators (Ornithomimids) - Crypsis: ability to avoid detection (camouflage, hiding, odor-masking chemicals) - Finite element analysis: computer simulations that apply set material properties to a digital object and report data on how stresses are dispersed through the object (used to evaluate function of certain adaptations) - determining how well a dino could see, hear or smell can be estimated by examining brain cases (size of orbits, inner ear cavity, etc.) - herbivores often have eyes on the side of their head (to spot predators) - predators often have stereoscopic vision: field of vision in both eyes overlap, allowing better depth perception (animals that fly or climb)

- some predators rely on ambush, some stalking/pursuing, some endurance - some predators hunt in groups (social) - Albertosaurus lived in groups rather than solitary - agonistic behaviors: fighting and aggressive behavior between members of the same species - ritualized agonistic combat: elk bashing antlers - Pachycephalosaurs had thick domed skulls for head butting competition (strut-like bone) - trackways and monospecific bonebeds tell us some dinos formed groups (ceratopsians, sauropods, ornithopods, hadrosaurs, tyrannosaurs) - juvenile Pinacosaurus were social and lived in groups while the adults may have been solitary - Paleopathologies: healed injuries, evidence of disease, infections, cancer, arthritis - Nonlethal Face Biting: common agonistic behavior (seen in tyrannosaurs and modern crocodiles) - Triceratops likely locked horns in mating battle rituals, injuring the squamosal area of the skull

Lesson 7 - What is a Species? Carl Linnaeus - developed a system for naming organisms (taxonomy) - Taxonomy = naming/organizing organisms into related groups - Binomial Name: 1. Genus name (capitalized) 2. Specific epithet (lower case) ex: Tyrannosaurus rex, Homo sapien (italicized) - Rule of Priority: once given a name, it can not be changed - Holotype Specimen: physical example of a new species that shows unique characteristics that make it distinct - Interspecific Variation: individuals differ because they belong to a different species - Intraspecific Variation: individuals differing in morphology but belonging to the same species: • sexual dimorphism • ontogenetic variation (old/young) • individual variation - Taphonomic Variation: plastic deformation - Biological Species concept: a species is a group of organisms that can successfully interbreed - Population: grouping of organisms that live in the same geographic area and interbreed - Morphological Species Concept: a species is a group that share a certain degree of physical similarity - Lumpers: palaeontologists that require MANY DIFFERENCES before they classify 2 species - Splitters: palaeontologists that require FEWER differences - Hesperonychus: pelvis bones tightly fused - 3-dimensional geometric morphometrics: using specific landmarks on bones to quantify differences and distinguish a species

Lesson 8 - EVOLUTION Evolution has 4 basic Principles: 1. traits must be heritable 2. there must be variation 3. traits must increase fitness 4. selection is partly due to environmental factors = differential success, variation, and competition lead to a change over time - as a beneficial trait becomes more widespread, many others will become the norm - evolution of a new species does not require the extinction of its ancestor - how well a trait improves fitness decides if it is beneficial or not and therefore whether it will be passed on or not - Natural Selection: competitive selective process where detrimental traits are discarded and advantageous traits retained - organisms are grouped together based on their most recent shared common ancestor - all dinosaurs are grouped together because they evolved from a single species of amniote tetrapod - Character: any heritable trait that can be described and labeled - Shared Derived Character/Synapomorphy : character present in 2 or more groups and their common ancestor, but not in a distantly related group (predentary in ornithischians) - Convergent Evolution: evolution of similar traits in 2 different lineages (when they must adapt to similar environments/modes of life) • evolution of wings in flying vertebrates … birds, pterosaurs, bats - Parsimony/ Occam’s Razor: “all other things equal, the simplest answer is the right one” - Phylogenetic Tree: sequence of relationships between organisms with the fewest instances of convergent evolution • Nodes - where 2 branches diverge (point when 2 lineages shared a common ancestor) - Clade: group of species that share a node - contains the ancestor and all its descendants - Thomas Henry Huxley: colleague of Darwin’s who recognized that birds evolved from dinosaurs (Archaeopteryx) - Birds and theropod dinos share many characteristics > Sinosauropteryx: first non-avian dino to be found with feathers - the line between bird and dinosaur is blurry

- Definitions of Bird: 1. Archaeopteryx and its descendants > ? may be related more closely to dromaeosaurids 2. feathered dinosaurs > ? tyrannosaurs were birds… 3. Flying dinosaurs > ? which dinosaurs could fly and which could glide 4. Crown Dinosaurs: the last common ancestor of all extant birds > favoured LESSON 9 - Stratigraphy and Geologic Time - Principle of Superposition: the tendency for rock layers to be chronologically stacked - Igneous rocks that form from volcanoes may vertically cut through horizontally arranged layers - Mountain Building events may tilt, fold. or flip rock layers - Stratigraphy: using arrangement and composition of rock layers to interpret geological history - Formation: uninterrupted sequence of rocks made of multiple layers of similar rock formed under similar conditions - Relative Age: how old one layer is relative to another - Absolute Age: how old in years a layer is - Radiometric Dating: the use of isotopic ratios to determine the age of rock - Isotope: a variant of a chemical element that has an unusual number of neutrons - Decay products: unstable isotopes that undergo radioactive decay, where new atoms with different compositions results - When a new rock forms, its isotopes and decay products match the environment’s - Mass spectrometer measures the isotope ratio of rock (tells us when the rock formed) - sedimentary rock can NOT be dated while igneous rocks CAN, so if sedimentary rock is found between 2 layers of igneous rock, we can assume it is younger than the lower and older than the higher - fossils may be buried by volcanic ash, a key tool in dating

- Geo...