Final Exam (Lectures 25 - 35) Flashcards

Question

Archosauromorpha: Ornithodira: "Dinosaurs": Two lineages?

Answer 1

1) Ornithischia 2) Saurischia (includes birds) * paraphyletic group if birds are excluded

Answer 2

- moving legs under body shortened pubofemoral and ischiofemoral muscles - shorter muscles less effective - both lineages therefore "reorganized" pubis and ischium but in different ways - both lineages with secondarily quadrupedal forms

Answer 3

* birds don't belong in this group - "bird hips" = pubis downward, toward the tail, parallel with ischium, resembles modern bird hip (but secondarily derived in birds) - all herbivores - predentary (unique) and premaxilla form beak for grasping vegetation - low-crowned cheek teeth

Answer 4

bird hips=pubis downwards, toward tail, parallel with ischium lizard hip=pubis forward

Answer 5

- Ornithischians radiated into more diverse morphological forms than did herbivorous saurischians - not as bipedal as large saurischians

Answer 6

1) Thyreophora: "shield bearers", quadrupedal, armoured dinosaurs (stegasaurs, ankylosaurs) 2) Ornithopoda: "bird feet", bipedal, hadrosaurs (duck-billed dinosaurs, parasaurolophus), iguanodon, hypsilophodon 3) Marginocephalia: "ridge head", bipedal pachycephalosaurs, quadrupedal ceratopsian (triceratops, protoceratops, pentaceratops)

Answer 7

- front legs shorter than hind legs - grazed on low-growing plants - horny beak at front of jaws - teeth unspecialized - two pairs of spikes on tail - two rows of plates along vertebral column as armour for protection and heat exchange (highly vascularized)

Answer 8

- fused osteoderms in skin of neck, back, hips, tail - bony plates on skull, jaws, eyelids - short tails with mace-like club - fused, distended vertebrae - horny spines on back and sides

Answer 9

- first recognized dinosaur fossil - "bird feet" = three-toed feet (but many early forms with four) - no armour - more mobile - horny beak - bipedal, but some quadrupedal while eating - one of the most successful herbivore groups in Cretaceous due to sophisticated chewing apparatus (hypsilophodon) - specialized teeth (unusual in anything but mammals)

Answer 10

- derived ornithopods - many diverse rear teeth that are rapidly replaced - stiff tail strengthened by ossified tendons for balance (no drag on the ground) - evidence of extended parental care (ex-Maiasaura="good mother reptile")

Answer 11

- with or without crests formed by nasal and maxillary or premaxillary bones - nasal passages ran through crests that may have been used for species-specific vocalization and visual displays (especially in hollow-crested forms)

Answer 12

- "good mother reptile" - migrated to well-defined nesting grounds - warming of eggs likely provided by vegetation (seen in extant crocodilians and some birds) - extended parental care - parent may have responded to high-frequency vocalizations of juveniles

Answer 13

- "ridge head or fringe head" - shell of bone extending back over occipital region of skull - highly specialized herbivores - last group of ornithischians to appear in fossil record

Answer 14

- "thick headed" - bipedal - thick bony dome on skull roof not used as battering ram but for flank-butting or wrsetling

Answer 15

- early forms bipedal with no head frill - later forms obligate quadrupeds (ex-Protoceratops) - frill past shoulders in more derived forms - origin for powerful jaw muscles - knifelike teeth for shearing vegetation - sexual dimorphism in frills also suggest role in mating - frills may also have functioned in thermal regulation (large surface area)

Answer 16

- modest frill over neck formed by enlargement of parietal and squamosal bones - without nasal horn - obligate quadruped

Answer 17

-nasal and brow horns in derived forms likely for defense and intraspecifc combat

Answer 18

Quadruped: four feet Tetrapod: a phylogenetic grouping that have four feet Bipedal: uses only two legs for walking

Answer 19

- "lizard hips" = pubis forward | - true bird hip seen in modern birds evolved later within this lineage, in the maniraptors

Answer 20

1) Sauropodomorpha: mostly quadrupedal herbivores | 2) Theropods: bipedal carnivores, includes birds

Answer 21

- "long necks" due to shifts from low-growing flora to taller conifers during late Triassic - Prosaurapods and Sauropods

Answer 22

- Brachiosaurus="arm lizard" - Diplodocus with teeth only at front of mouth - Apatosaurus=Brontosaurus? with longer arms, longer forelegs than hindlegs * largest terrestrial vertebrates known * one of the most long-lived groups of dinosaurs - found on all continents except Antarctica - long necks and tails for defense or combat - tail stiffened by hemal arches

Answer 23

- a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract - are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth

Answer 24

not gastroliths but likely a symbiotic microorganism that helps with the long passage time of food during digestion

Answer 25

- vertebrae with pleurocoels (hollow) for air sacs - massive vertebrae with well-developed neural arches - ligaments transmitted force from one arch to adjacent ones - head and tail supported by heavy ligament - track marks show tail carried, not dragged - massive elephant-like feet - limbs held directly under the body - knees locked when walking

Answer 26

set of hollow depressions on the lateral portions of the vertebrae in dinosaurs, which served to decrease the weight of these bones without sacrificing strength

Answer 27

- thought weight could not be supported on land - must be semi-aquatic - contradicted by recent mechanical analyses of the skeleton

Answer 28

- high and stable body temperature without elevated metabolic rates - "gigantothermy" - energy requirement for endotherm probably would have been prohibitively high - not endothermic or Exothermic but gigantothermic - are probably both warm blooded and cold blooded

Answer 29

- trackways suggest herdlike behaviour with young in the middle - laid eggs in nests dug in soil - nests are too close together to allow incubation (so no incubation) - no direct evidence of parental care (unlike Hadrosaurs)

Answer 30

- thousands of sauropod eggs found - found in clusters up to five feet long - cover one square mile

Answer 31

Sauropods: - single row of teeth - food processing does not occur in the mouth but by a symbiosis with a microorganism - no direct evidence of parental care Hadrosaurs: - multiple rows of teeth - lots of food processing occurs in the mouth - evidence of parental care

Answer 32

- bipedal carnivores - includes birds - have furcula (wishbone, formed by fusion of clavicles, preceded appearance of flight, a synapomorphy shared with birds) - some with protofeathers = single hollow filaments, composed of beta keratin unique to feathers - reports in 1996 of non-avian dinosaurs with feathers in more derived theropods - early offshoots are ceratosaurs and carnosaurs

Answer 33

- wishbone - formed by fusion of clavicles - preceded appearance of flight - synapomorphy of Theropoda and birds

Answer 34

- "coel"=hollow, "uro"=tail, "saur"=lizard - monophyletic subgroup of theropods - excludes ceratosaurs and carnosaurs - includes tyrannosaurs and maniraptors (dromeosaurs and birds) - synapomorphy=light bones, hollow tail vertebrae - many with feathers

Answer 35

- early tyrannosaurs were small with long arms and legs - there was an increase in skull, jaw, teeth size and strength then overall size - ex) T-rex

Answer 36

- from Late Cretaceous - short front legs - only 2 small fingers on each hand - not a fast runner - used skull as a weapon - a lizard hip due to pubis forward - large head but lightened by antorbital and mandibular fenestrae - powerful jaw muscles (alligator and tasmanian devil only extant species capable of exerting comparable force) - serrated teeth up to 15cm long (bite marks on Triceratops pelvis more than 11mm deep)

Answer 37

- "hand snatchers" - "mani"=hand, "rapt"=seize - raptors, dromeosaurs, birds

Answer 38

1) large bony sternum (important for flight muscle attachment) 2) semi-lunate bone in wrist (for sideways flexing and rotating of wrists to seize prey and in birds to create air flow during flight) 3) opisthopubic condition = pubis pointed backwards 4) rear feet with 3 forward pointing toes and 1 pointing backwards (hallux) 5) feathers (more complex than in tyrannosaurs, down-like tufts and feathers with symmetrical vanes)

Answer 39

pubis is pointing backwards

Answer 40

- fast moving predators that used huge claw on hind foot to attack large prey - ex) Deinonychus - ex) sinornithosaurus - ex) Velociraptor - ex) Oviraptor

Answer 41

- "terrible claw" - sickle-like claw on 2nd toe of hind foot - capable of disemboweling prey with a kick

Answer 42

- from Cretaceous | - have more complex feathers

Answer 43

- fast - large grasping hands - clawed hind feet - pack hunting - had feathers (evidence due to quill knobs to attach the feathers along a bone)

Answer 44

- originally thought to steal eggs from other dinosaurs because a skeleton was found near what was thought to be Protoceratops nest, but fossilized embryo in similar egg found to be Oviraptor - has feathers

Answer 45

- 23-24 species - only survivors of Crurotarsi lineage - alligators: 2 species (American and Chinese) - caimans: 6 species - alligators and caimans have a broad snout, varied diets and live in freshwater - crocodiles: 14-15 species, narrow snouts=fish eaters, broader snouts=feed on turtles, terrestrial animals, salt glands on tongue for those that live in salt water - Saltwater crocodile record is 8.6 m in length - single species of gharial, have narrowest snout, are fish eaters

Answer 46

1) rottweiler (335) 2) great white shark (400) 3) hyena (800-1000) 4) crocodilian (5000)

Answer 47

- muscles to close jaws are very powerful (can crush adult turtle, only extant vertebrate with jaws of comparable power to T. rex and Tasmanian devil) - but muscles to open jaws are very weak - primarily aquatic - hunt in water - Nile crocodile ambushes large mammals that come to drink - very sensitive pressure receptors on jaws (similar in function to the lateral line, but not in structure!) - drags prey underwater to drown - can gallop quickly on land - bites off large pieces and swallow whole - sometimes lets meal decompose for easier dismembering - up to 3000 teeth in their lifetime - teeth are like a conveyor belt and replace each other - secondary palate allows them to breathe while mouth full of water - legs nearly vertical under body

Answer 48

pressure receptors on the jaws

Answer 49

- 4 chambered heart with fixed septum - left aorta and Foramen of Panizza (connecting left and right aortic arches) allows mixing of oxygenated and deoxygenated blood - permits shunting of blood between pulmonary and systemic circuits - intricate control over where blood flows (to lungs, limbs, viscera) and whether deoxygenated or oxygenated blood - at rest, during breath holding or when active - accomplished in turtles with transient septum - has 2 atriums, 2 aortas, 2 ventricles which allows for mixing of blood (does this when holding their breath)

Answer 50

- use sound for communication (vocalization, slapping head and tail against water) especially important in dense swamps where vision is limited - distress squeak from young elicits response even from unrelated adults - calls of pre-hatchlings stimulate parents to excavate nests - parents help open eggs and carry young to the water = extensive parental care - precocial hatchlings but stay near mother for some time (2-3 years) - similar parental behaviours also seen in birds and non-avian dinosaurs suggests common ancestors

Answer 51

Precocial: hatch well-developed (advanced for their age), in crocodilians Altricial: very poorly developed (eyes aren't even developed yet), in birds

Answer 52

- temperature-dependent sex determination - females at low temps, males at high temps - both sexes produced in each nest (top and centre is warm=males, bottom and side are cooler=females) - construction of levees that are hotter than nesting sites in marshes and filling in of marshes and swamps causes highly male-biased sex ratios - effects of global warming or cooling could result in more highly biased sex ratios (all males=hotter and all females=colder)

Answer 53

- ex) Caudipteryx - centre of gravity near hind limbs - shallow trunks (without deep sternum) - long bony tails - full sets of teeth - symmetrical feathers = flightless

Answer 54

symmetrical=flightless | asymmetrical=capable of flight

Answer 55

- centre of gravity shifted forward toward wings - larger sternum - shortened bony tail and pygostyle - asymmetrical feathers=flight - changes to shoulder and wrists

Answer 56

- feathers preceded flight - symmetrical feathers and skeletal structure suggests that non-avian theropods were flightless - asymmetrical feathers necessary for flight

Answer 57

- Archaeopteryx - forelimbs large enough to fly - although likely also in other proavians by late Jurassic

Answer 58

- for social display - covering the nest - insulation for smaller Dromeosaurs (in larger ones, body temperature is above ambient without elevated metabolism so no need for feathers)

Answer 59

chicken from hell

Answer 60

- originated in Late Cretaceous - 10,000 species - phylogenetic relationships poorly understood - two divergent lineages: Paleognathae and Neognathae

Answer 61

- "old jaws" - 60 species - all (mostly) flightless - Tinamous (can fly but poorly and reluctantly) and Ratites (emus=1 species, cassowaries=3 species, ostrich=1 species, rheas=2 species, kiwis=3-5 species, good sense of smell)

Answer 62

ostrich | -has two toes on each foot, resembles hoof, have symmetrical feathers=flightless

Answer 63

- "new jaws" - Passeriformes=6000 species (most speciose), perching birds, songbirds - Galliformes=fowl, peacock, peatowl - Waterfowl=Canada goose, ducks - Woodpeckers - Apodiformes="footless", hummingbirds - Gulls, puffins, shorebirds - Albatrosses, petrels - Cranes, rails, coots - Flamingos - Herons, storks, ibises, bitterns, pelicans - Penguins - Falconiformes - Hawks, eagles, buzzards (diurnal) - Owls (nocturnal) - Parrots (400 species) - Pigeons - Kingfishers, kookaburras

Answer 64

Apodiformes

Answer 65

393 species of birds in Manitoba, since they can leave during the winter time (fly away) vs 16 amphibians and five squamates (since are stuck to live through the winter)

Answer 66

- Passeriformes: 6000 species (most speciose), perching birds, songbirds - Apodiformes: "footless", hummingbirds - Galliformes: fowl, peacock, peatowl

Answer 67

Trumpeter swan (20 kg)

Answer 68

- 90% keratin plus lipids, water and pigments | - makes them light but strong and resilient

Answer 69

- largest feathers - give bird shape (fill out) and colour - include flight feathers (remiges) and tail feathers (retrices) - important for streamlining in air - reduce turbulence

Answer 70

provide thermal insulation beneath contour feathers

Answer 71

- vanes: serves as an airfoil (produces lift from movement of air over it), protects downy undercoat, sheds water, reflects or absorbs solar radiation - barbules: maintain structure, easily corrected by preening (allows them to realign their feathers properly), like velcro

Answer 72

- provide waterproofing | - are oil glands

Answer 73

- common around mouth and eye - filter out foreign particles - tactile sense organs (around mouths of nighthawks) - not eyelashes or hairs! are specialized feathers

Answer 74

- lack urinary bladder - lack teeth - only have left ovary, develop only one egg at a time - gonads regress after breeding - hollow (pneumatic) bones (in large birds but less in diving birds like penguins and ducks) - air spaces in skull - sternum, pectoral girdle, humerus with air sacs - skull of crow paper thin

Answer 75

birds all oviparous

Answer 76

- rigid trunk - thoracic vertebrae fused (synsacrum) - fused caudal vertebrae (pygostyle) - wings positioned above centre of gravity - keel (except in flightless birds) important for attachment of flight muscles

Answer 77

``` Flight muscles, leg muscles Hummingbirds: 25-35, 2 Hawks/owls: 20, 10 Ducks: 15-30, 15-30 Rails: 10, 20 ```

Answer 78

- dark leg "meat" with myoglobin for aerobic metabolism - white breast "meat" without myoglobin - birds capable of strong sustained flight have dark breast "meat" or muscles - myoglobin in flight muscles transports oxygen to muscles

Answer 79

- lift - gravity - thrust - drag

Answer 80

- lift achieved by wing shape - dorsal surface convex, ventral surface concave - air pressure reduced over wing, increased under wing - inner wing (secondary feathers) provide most of the lift - primary feathers (on hand) for thrust (propulsion) - drag generated at wing tips due to turbulence, reduced by lengthening wing or through tapered/notched wing tips

Answer 81

reducing area at tip

Answer 82

notched wing tip

Answer 83

high aspect ratio: long, narrow wings, high lift-to drag ratio (ex-swallow wing), provide less power, poor for sudden acceleration low aspect ratio: short wings, better for burst acceleration, not good for long-term gliding (ex-pheasant wing)

Answer 84

- Hummingbird has long hand bones to generate maximum thrust from primaries - Whereas albatross has longer humerus (arm) for greater lift while soaring

Answer 85

- downstroke produced by contraction of pectoralis major - upstroke in small birds mostly passive recovery stroke, resulting in some deceleration - large birds generate thrust on upstroke, with figure eight movement of primaries - powered upstroke produced by contraction of supracoracoides (small, pale muscle=5% but bigger in species relying on powered upstroke for fast steep take-offs and aerial pursuits = 33%) - V-formation more energetically efficient (geese and pelicans), especially when flapping alternated with gliding

Answer 86

- ex) ostrich - similar as those of quadrupeds - reduction in number of toes - more limited due to balance constraints - surface area reduction

Answer 87

ansiodactyly and zygodactyly

Answer 88

- 3 forward pointing toes and one opposable hind toe - developed in passerines ("perching birds") - weight of resting bird "locks" toes around perch - climbing nuthatches with long claw on hallux

Answer 89

- 2 toes forwards and 2 backwards - for perching or climbing on vertical surfaces - woodpeckers, parrots - also seen in chameleons

Answer 90

- beaks and tails help climbing and foraging on vertical surfaces - ex) woodpeckers use tail for support - pygostyle and free caudal vertebrae enlarged - stiff tail feathers (don't shed tail feathers all at once) - unusual to use wings - ex) hoatzin uses wings to climb, due to weak fliers - young with claws on first two digits of wing like Archeopteryx (first bird capable of flight) - weak fliers - perhaps related to specializations for herbivory

Answer 91

- 400 aquatic bird species - hind limbs specialized for surface swimming and located posteriorly for steering control where large leg muscles interfere less with streamlining (balancing selection for swimming and flying) - feet with webbing between three forward toes (ducks) or all four (pelicans, cormorants) or lobed (grebes) - wider body for increased stability in water - convergent evolution in several lineages - modifications to plumage to increase buoyancy, insulation, and waterproofing (preen gland to cover plumage in oil) - foot-propelled (grebes, cormorants, loons, diving ducks) or wing-propelled (diving petrels, penguins,auks, ducks) divers

Answer 92

- reduced pneumaticity of bones if both flying and diving, since they have to be lighter to fly - ability to expel air from plumage before diving - some penguins swallow stones

Answer 93

- tolerance for high carbon dioxide in blood - constriction of peripheral blood flow (to concentrate blood in body core), reduction in heart and metabolic rate - large blood volume, myoglobin-rich muscles, increase O2 storage capacity

Answer 94

- beaks, tongue, feet involved in prey capture - light, horny beak rather than teeth - beaks very diverse and specialized - skull kinesis important to increase gape in both vertical and horizontal planes - long, elongated tongues may also be specialized for food gathering - ex) green woodpecker (tongue 4x length of beak with barbs on tip, impales ants to pull from tunnels, tongue=hyoid apparatus) - hawks and owls use talons - carry fish headfirst, important for streamlining when in the air - ex) hummingbird uses capillary action, no barbs on tip of its long tongue

Answer 95

- crop: enlarged portion of esophagus for temporary food storage - specialization for carrying, processing food since no hands or teeth - used to carry food for nestlings - crop milk produced by both sexes in doves and pigeons - high in lipids and protein, similar in composition to mammalian milk but different in containing intact cells - Regurgitate cells high in protein for nutrition for the young - crop milk production stimulated by prolactin (induces lactation in mammals) - esophagus of many other species (flamingos, emperor penguins, gray jay and other seed eaters) produce similar nutritive fluid

Answer 96

- using foregut fermentation (bacteria and protozoa) - Symbiotic microorganisms break down plant cell wall - Release volatile fatty acids for absorption

Answer 97

- structure related to diet - expansible for storage in carnivores - involved in mechanical breakdown of food in insectivores, seed eaters (no teeth!)

Answer 98

1) Proventriculus: anterior glandular stomach, secretes acid and digestive enzymes 2) Gizzard: posterior muscular stomach, thick muscular walls for mechanical, sometimes with aid of small stones (gastroliths)

Answer 99

- small intestine is the main site of chemical digestion and absorption with enzymes from pancreas and intestine - short large intestine - passage time generally rapid, few minutes to few hours in carnivores, fruit eaters, up to a day in herbivores (more plant material in diet=longer intestine) - intestine changes length seasonally with changes in diet and during migration - pair of ceca at junction of small and large intestines in most birds where symbiotic microorganisms ferment plant material (hindgut fermentation) - large in herbivores and omnivores (ducks, geese, cranes)

Answer 100

- wastes stored in cloaca while water reabsorbed - uric acid precipitated as urate salts, water returned to bloodstream - even more water conservation in species with salt-secreting glands - bird "poop" = white urate salts+dark fecal matter - concentrated uric acid, urate salts lighter than dilute urine

Answer 101

- vision important for flying rapidly through 3D space - eyes, optic lobes, cerebellum large - nictitating membrane lubricates and protects eye (predatory sharks have nictitating membrane to protect eye when hunting/eating prey) - aquatic birds have flexible lenses for vision in air and water or may use nictitating membrane as contact lens (like four-eye fish) - eyes on side of head with wide visual field - eyes at front allow for binocular vision (owls)

Answer 102

- hearing particularly sensitive in frequency range of own vocalizations - No external ears, would interfere with streamlining - owls with especially sensitive hearing, some nocturnal or crepuscular, have large tympanic membranes, well-developed auditory centers - facial ruff focuses sound, asymmetric in some species for localization of sound - skull even asymmetric in many species to help localize sound - can hear infrasound, very low frequencies (thunderstorms, winds blowing across valleys)

Answer 103

Don’t have ears! What looks like ears are just tufts of feathers used for visual cues (not involved in hearing at all)

Answer 104

- sense of smell poorly developed in general - relatively large olfactory bulbs in some species (ground nesting and carnivorous birds) - involved in navigation in some birds (albatrosses, petrels, homing pigeons) - kiwis have very good sense of smell to find worms under the ground - vultures (carnivores) also with good sense of smell

Answer 105

- sex-specific plumage patterns not visible to us | - UV reflective urine trails left by prey

Answer 106

-detect changes in altitude and weather (differences in air pressure)

Answer 107

-magnetite in heads of homing pigeons allows them to detect magnetic fields

Answer 108

aren't capable of flight

Answer 109

very good at running, but not flying

Answer 110

- low aspect ratio: short and wide wing | - fast flyer (accelerate) but can't sustain for a long time (soaring)

Answer 111

- all birds oviparous (all archosaurs), may be related to flight and endothermy - laying one egg at a time to reduce weight when flying - brooding permits control over incubation temperature - all birds and mammals with genetic sex determination, females are heterogametic sex (WZ) and males (ZZ)

Answer 112

- depressions in the dirt or sand - nests in numbers - on cliffs where predators can’t go - weaver birds - in water by floating - in trees - Megapodes (Australian bush turkey)

Answer 113

- incubation by one or both parents - brooding behaviour induced by prolactin - incubation period lasts from 10 to 80 days - generally shorter in small birds, where predation high

Answer 114

hormone that induces lactation and crop milk

Answer 115

emperor penguin

Answer 116

altricial: chicks, passerines precocial: megapodes, ducks, shorebirds somewhere in between: gulls

Answer 117

1) social monogamy 2) polygyny 3) polyandry 4) brood parasitism

Answer 118

- most birds form pairs for one or more breeding seasons - Swans form pair bonds for life, for practical reasons to care for young - occurs where nest sites and food are evenly distributed, where one male can't monopolize resources - where both parents are needed to care for young, more prevalent in species with altricial young, where predation is high (colonial seabirds) - extra-pair copulations - form pairs but often unfaithful - young all have different fathers, but only one male sits with the female in the nest - social monogamy does not mean genetic monogamy - bet-hedging may be beneficial - genetically diverse offspring more beneficial

Answer 119

- where male mates with more than one female - if male can monopolize critical resource (resource defense polygyny) - where males compete for females through dominance or displays (male dominance or lek polygyny), don't control resources but compete for females - ex) prairie chickens, peacocks - males do not control access to resources - hypothesized instead that elaborate visual displays may be indicator of male quality - males not involved in parental care

Answer 120

- females "emancipated" from parental responsibilities - rare - female provides no parental care - ex) spotted sandpiper: predation on nests is high, females provide replacement clutches which males will incubate - ex) red phalarope: colourful females court males, female is larger, female flies south but male stays in the nest, lay eggs in male's nest

Answer 121

- 100 species obligate brood parasites - eggs laid in nests of other species - ex) cowbirds, cuckoos - eggs tend to hatch quickly - "parasitic" chick may kill host's young - “Evolutionary arms race” where the host tries to fight the brood parasite - gets more resources due to parasite baby has bigger and more colourful mouth which elicits a feeding response from mother - Parents don’t recognize eggs or do they fear retaliation? - Ex) Brown-headed cowbird in Manitoba

Answer 122

birds that breed at high latitudes and migrate south for winter

Answer 123

- low food availability at higher latitudes in winter - cold temperatures in winter - high food availability at higher latitudes in summer - longer days for foraging - perhaps fewer predators at higher latitudes ex) robin (bird in Manitoba) that migrates over the winter and goes down south

Answer 124

- short-tailed shearwater: migrates 15,000 km from North Pacific to breeding sites in Southern Australia, have long tapered wing for soaring, fifth for longest migration of birds - Arctic tern: breeds in Arctic, overwinters in Antarctic, 18,000 km migration, longest migration for birds

Answer 125

- gonadal regression - premigratory fattening - coordination of internal rhythms with external stimulus (usually day length) so arrival corresponds with available food for young (insect emergence) - show a twice-yearly migratory restlesness

Answer 126

Put bird on an ink pad and if they go north=spring and if they go south=fall

Answer 127

- ex) homing pigeons use the sun as a compass on clear days which requires an internal clock - on cloudy days, use magnetic cues (If put magnet on their beak where magnetic cues comes from, they get all confused) - recognize familiar odours - many birds migrate at night (sparrows, wrens, thrushes) so use star patterns and/or magnetism

Answer 128

- Turning lights on 6 hours earlier for weeks (off by 1/4 day) - Sunny days: off course by 90 degrees (1/4 circle) - Cloudy days: perfectly fine internal clock of the birds, since don’t use the sun but use some other method

Answer 129

- extreme cold of the Antarctica - large body size and shape minimizes surface area:volume - insulating feathers good on land to trap air and shed water - Black feathers on dorsal surface absorb more heat (solar radiation), white on ventral surface used for counter shading when swimming in the water, but feathers useless in water for insulation - subcutaneous fat for insulation in water - turbinates recapture heat escaping through breath - cooling of flippers and feet minimized by countercurrent heat exchange (Like fast swimming fishes, recirculate heat in the body), minimize contact with ice by resting on heels and tail, muscles for their control in warmer body core - huddle in groups of up to several thousand penguins due to -30 degrees Celsius in Antarctica, shuffle from outside to inside the circle to take turns warming each other up - males incubate eggs on feet otherwise if egg touched the ice it would kill the embryo almost immediately, also they fast for months and lose 40% of their body weight

Answer 130

for olfaction and penguins also use it to retain warm air in nasal passages (recycles air)

Answer 131

- sauropsids: reptiles, "dinosaurs" and birds (20, 000 extant species) - synapsids: mammals and extinct relatives (5,500 extant species)

Answer 132

- single temporal fenestra - radiated into terrestrial habitats before diapsids did (in Paleozoic) - top carnivores - medium to large size - only mammals survived past Cretaceous period (were much smaller)

Answer 133

1) Pelycosaurs (paraphyletic) | 2) Therapsida (non-mammalian and mammalian)

Answer 134

- NOT dinosaurs - carnivores with large, sharp teeth - no evidence of locomotory specializations or endothermy - more aquatic than therapsids - ex) Dimetrodon: reptilian-like, sails on back likely for temperature regulation, elongated neural spines, Paleozoic, more aquatic than Theraspids, went extinct 250 mya

Answer 135

- more mammalian-like - more derived than pelycosaurs - locomotory specializations (more slender limbs) - feeding and respiratory specializations that may have permitted increased metabolic rate (possibly higher growth rate, coronoid process on dentary and enlargement of temporal fossa for insertion of jaw muscles) - more differentiated teeth (multicusped teeth, canine, incisors) - separation of nasal passages and oral cavity (secondary palate) - larger infraorbital foramen (sensory nerves from snout) - includes Cynodonts, although they remained a relatively minor component of terrestrial fauna with rise of dinosaurs during Triassic

Answer 136

1) Cynognathia: "dog jaw", large carnivores and diverse herbivores 2) Probainognathia: "progressive jaw", smaller and less specialized carnivores and insectivores, lineage that gave rise to mammals

Answer 137

- "dog tooth" - general trend toward smaller body size before the extinction of dinosaurs - non-mammalian cynodonts mostly extinct by end of Triassic - diversification into larger, more specialized only after the extinction of dinosaurs

Answer 138

Endothermy: 1) turbinates and loss of parietal foramen (Ex) Pelycosaur-used behavioural thermoregulation, sail for endothermy, have pineal gland (third eye)) Higher metabolic rate: 2) increased feeding efficiency (larger temporal fenestra and masseteric fossa, changes in lower jaw and jaw joint, greater specialization of dentition) 3) increased respiratory efficiency (secondary palate and loss of lumbar ribs suggesting diaphragm 4) greater activity levels (more upright posture)

Answer 139

- in ancestral synapsid jaw (pelycosaur), dentary forms anterior half of lower jaw - postdentary bones from posterior half - articular bone in lower jaw articulated with quadrate bone in skull - in Cynodonts, progressive increase in size of dentary associated with increased musculature of lower jaw - decrease in postdentaries - in most derived cynodonts, condylar process of dentary contacted squamosal bone of skull, forming new jaw joint - only dentary-squamosal jaw hinge in mammals

Answer 140

Ancestral jaw hinge= A (articular) and Q (quadrate) | Derived jaw hinge (only in mammals)= D (dentary) and sq (squamosal)

Answer 141

- bones from old jaw joint part of mammalian middle ear (post dentary bones move to middle ear that are much smaller now and dentary is devoted largely to feeding) - quadrate becomes the incus and the articular becomes the malleus - need for greater feeding efficiency in endothermic synapsids led to conflict between hearing and eating

Answer 142

- hair and mammary glands but they don't fossilize well - use of a new jaw joint - larger brain - inner ear - teeth features

Answer 143

- Morganucodon - from Early Jurassic - no fossilized hair found - evidence of Harderian gland (which secretes lipid used for insulating fur in extant mammals) suggests it might have had hair - Harderian gland absent in larger non-mammalian cynodonts

Answer 144

- di=two - two sets of teeth - ex) humans have a set of baby teeth that we lose and then gain a second set of teeth, our adult ones - milk (deciduous) teeth = incisors, canines, premolars - adult teeth also include molars - very unusual - seen in early mammals as well

Answer 145

- multiple sets of teeth | - teeth of most vertebrates

Answer 146

- provides precise occlusion between upper and lower teeth - allows for thorough chewing - complex arrangement of teeth for many different functions

Answer 147

- only two sets in lifetime | - requires very resistant enamel

Answer 148

- insectivorous - with good sense of smell - nocturnal - without external ears (pinnae) and nipples

Answer 149

- lactation feature of early mammals - teeth come in sometime after birth, first six months in humans are nursing so don't need teeth - non-mammalian cynodonts likely physically unable to suckle - only mammals with pharyngeal anatomy permitting suckling - facial muscles and mobile lips also important - muscles also important later for facial expressions and communication - mammary glands appear similar to sebaceous glands associated with hair - may have originally secreted pheromones or had antimicrobial properties for protection of eggs in nest - later selection for nutritive function - reproduction no longer tied to seasonal food supplies - viviparity allows young to be born small and grow later - ex) birds time migration perfectly to time eggs with insect high food supply season

Answer 150

1) mammary glands 2) hair 3) lower jaw made up only of dentary bone (better preserved in fossil record) 4) middle ear with three bones (better preserved in fossil record) 5) main systemic arteries derived from left aortic arch 6) anucleate red blood cells in adults 7) alveolar lungs and diaphragm (increase surface area for gas exchange)

Answer 151

- more room for hemoglobin - more oxygen - bendier to fit through capillaries

Answer 152

different types of teeth that have specific functions and specializations (incisors, canines, premolars and molars)

Answer 153

- seven cervical (neck) vertebrae - Ex) giraffes still have seven but just larger to form the longer neck - first two vertebrae are specialized into the atlas and axis which allow for rotation in two planes (complete range of motion) - Hint: Atlas is the god that had to hold the earth, so holds the globe of the head

Answer 154

- complex system - protection against physical, chemical, biological attacks - temperature regulation - communication - nourishment of young

Answer 155

amphibians but they have different mucous glands than mammals

Answer 156

1) eccrine glands: watery secretions, mostly on soles of feet or other surfaces for adhesion, over body surface in primates for evaporative cooling (in humans) 2) sebaceous glands: sebum lubricates and waterproofs hair, thick lipid secretion (ex-lanolin in hand lotion, produced by sheep, important for waterproofing) 3) apocrine glands: associated with hair follicles, for chemical communication, covers body surface in ungulates for evaporative cooling, thicker, more odorous sweat in human armpits, develops later in development 4) mammary gland: derived from some type of basal apocrine gland, originally antibiotic or pheromones, later nutritive

Answer 157

- sebaceous and apocrine glands - modified as scent glands - sebaceous=viscous secretions - apocrine=volatile secretions - used to mark territories - apocrine scent glands of skunks

Answer 158

- epidermal derivative of keratin (alpha keratin) - insulation by trapping air - longer hair=greater insulation - depth of layer increased with erector pili muscles (make hairs stand on end to make it look thicker) - cold, fear or anger stimulates contraction of muscles - goosebumps=erector pili muscles that have lost the hair part - communication (fear and anger) - camouflage (arctic animals where hair colour changes seasonally) - sensation (vibrissae) like whiskers for sensation

Answer 159

hindgut since foregut interferes with flight muscles

Answer 160

polygyny: one male mating with multiple females | ex) peacock

Answer 161

Pelycosaurs and Therapsids

Answer 162

- secretory glands - hair - claws, nail, hooves - horns

Answer 163

- accumulation of keratin protects end of digits - ex) cornified hoof (unguis) of ungulates - ex) human fingernail or cat claws

Answer 164

- entirely made of keratin (ex-rhino) | - or covering bony core (ex-cows, antelopes)

Answer 165

No, Antlers are not true horns, they are dead bone and are not covered by keratin

Answer 166

- large brain with infolded cerebellum - considerable innervation of the face that is important for lactation and communication - hearing and olfaction are dominant with external and movable pinnae for directional (bats) but some exceptions like humans (can't move ears) and aquatic mammals like dolphins (external ears would interfere with streamlining) - vision less important due to evolution as nocturnal animals (visual sensitivity more important than visual activity) - primates are unique due to having trichromatic colour vision

Answer 167

- unique to mammals - specifically for heat generation (10x more heat than regular fat) - especially important in newborns, hibernating species

Answer 168

- XY sex determination for almost all mammals | - monotremes have multiple sex chromosomes and is dosage dependent

Answer 169

5500 extant species (less than 10% of all vertebrates)

Answer 170

1) Allotheria (multituberculates): extinct 2) Prototheria (monotremes): "first", platypus 3) Theria: Metatheria ("middle", marsupials, kangaroos and koalas) and Eutheria ("true", placental mammals)

Answer 171

- 5 species: 1 platypus and 4 echidnas - relics of a once more diverse lineage - "one hole or single opening" due to cloaca for urinary, defecatory and reproductive systems - lay eggs although retained in mother's body for some time and provided with additional nutrients - mammary glands but no nipples so young lick milk off fur of mother - toothless as adults - leathery bill or beak with electromagnetic receptors - venomous spur in males of the platypus, only produced during the mating season to fend off predators

Answer 172

- 330 species - marsupium="pouch" - two main lineages: 1) Ameridelphia (new world): opossum in South America, Virginia 2) Australidelphia (mainly Australia): Monitors del Monte ("little mountain monkey") found in South America = exception of one not found in Australia; Tasmanian devil (strongest jaws of any mammal, endangered), Tasmanian wolf (1933 went extinct, last one died), Numbat (Marsupial anteater), Eastern Barred Bandicoot (rodent-like, convergent evolution), Possum, Koala, Wombat, Red-necked wallaby, red kangarooo

Answer 173

Tasmanian devil found in Australia

Answer 174

- 5100 species - although not only mammals with a placenta since Marsupials do as well! - rapid radiation in evolution since interrelationships still somewhat uncertain - anteaters, sloths, armadillos=new world - pangolins (scaly anteaters)=convergent evolution, old world, more closely related to carnivorans and ungulates - aardvark=old world, convergent evolution, more closely related to shrews and elephants

Answer 175

- Rodentia: rodents, largest order (40% of all mammalian species, 2200 species) - Chiroptera: bats, "hand wing", more than 1100 species, second largest order - Primates: lemurs, monkeys, apes, humans, 300-400 species - Artiodactyla: cows, camels, sheep, deer, whales, "even toed ungulates" - Perissodactyla: horses, zebras, rhinos, tapirs, "odd-toed ungulates" - Sirenia: manatees and dugongs - Carnivora: pinnipeds, seals, walrus, sea lions, bears, dogs, cats, raccoons, weasels

Answer 176

Pinniped=fin foot, seal, walrus, sea lions, are the aquatic mammals, less fully aquatic than other marine mammals due to fur, external ears, hind limbs

Answer 177

- Sirenia - Carnivora - Artiodactyla

Answer 178

within Artiodactyla and sister group to hippos | *Artiodactyla is paraphyletic without Cetacea (previous group that contained the whales, dolphins and porpoises

Answer 179

- oviparous but with internal fertilization - two oviducts (uteri) meet at urogenital sinus - One hole = cloaca an all three systems empty in the cloaca (urinary, reproductive and digestive systems) - eggs retained in uterus and receive additional maternal nourishment (matrotrophy), yolk+uterine secretions - short incubation (2 weeks), altricial young - continued brooding (16 weeks) - low reproductive rate (1-2 eggs, 1 time per year) - only one functional ovary in the female

Answer 180

- viviparous (all other mammals) - athough marsupials with transient shell membrane and small amount of yolk - all therians with placenta formed from extraembryonic membranes (not just placental mammals) - although some general differences in type of placentation - all therian mammals have a placenta!

Answer 181

- ureters medial - in females, two lateral vaginas united at urogenital sinus and two uteri - male with forked penis - no cloaca - birth through median pseudovaginal canal - young "ejected" at end of estrous cycle - long period of lactation - young are altricial (poorly developed at birth) but with well-developed forelimbs and mouth (for suckling) - "migrate" unaided and attach to nipple to complete development - nipples within pouch in most marsupials (exceptionsare marsupial mice, opossums) - capable of embryonic diapause - asynchronous lactation for young at different stages

Answer 182

Pausing of embryonic development and resume later on in development -ex) red kangaroo

Answer 183

mother provides milk at different times based on the which stages the young are in

Answer 184

- ureters lateral - single, midline vagina in all - bipartite uterus - exception is higher primates (humans and chimps) have unusual single median uterus - no cloaca - separate urethral and vaginal openings only in primates and some rodents (no urogenital sinus) - young may be altricial (rodents, insectivorans, large carnivores) or precocial (ungulates) - all require lactation for antibodies and nutrition * relatively short lactation compared to gestation - some capable of embryonic diapause (roe deer, carnivorans, rodents, bats) - delayed fertilization (hibernating bats) - spontaneous abortion (mice)

Answer 185

uterus consisting of two parts

Answer 186

Males prone to killing young that aren't his, so female instead of wasting energy on birth and raising them undergoes spontaneous abortion when new males arrive into the population

Answer 187

- in gnawing mammals like rodents and rabbits, grow continuously, self-sharpening with enamel on anterior surface only - for fighting and display in elephant tusks

Answer 188

- used by carnivores to stab prey - lost or reduced in many herbivores - used for fighting and display (walrus, pigs, mouse deer) - most tusks are modified canine teeth, not incisors! - narwhal has the left canine tooth that is really long of upper jaw

Answer 189

- pierce and slice food (1 cusp) - molarized in many herbivores (ruminant artiodactyls, horses) due to abrasive diet - modifications to improve durability: high crowned teeth, ever-growing molars (rabbits, rodents) and molar progression (elephants, manatees)

Answer 190

-for more thorough chewing (2-3 cusps)

Answer 191

postcanine teeth specialized for shearing flesh

Answer 192

- anteaters, nectar bats, honey possum all have a very long tongue (Recall: woodpeckers, salamanders, frogs) - replaced with baleen in baleen whales like the blue whales, humpback whale and right whale

Answer 193

- cellulase required for digestion of cell walls - rely on symbiotic microorganisms in gut - fermentative digestion evolved independently in different lineages - recall: foregut and hindgut fermentation in birds

Answer 194

- cows and other artiodactyls with four chambered stomach - camels with three chambers - kangaroos, colobine monkeys, hippos, rodents with simple stomach without divisions - efficient since cellulose broken down before reaching small intestine - efficient in ruminants ("chewing their cud" regurgitate food back into mouth to continue chewing process) - added benefit of microbial protein - ruminants process food slowly, could starve to death with a stomach full of food - do poorly on high fiber, low quality diets

Answer 195

- horses and other perissodactyls - wombats, koalas, howler monkeys, elephants, rabbits, rodents - simple stomach but enlarged large intestine and cecum - generally less efficient since cellulose broken down after passage through small intestine - must chew very thoroughly - practice coprophagy - process food more quickly - do better on high fiber, low quality diets, but not where quality is limited (feral horses)

Answer 196

“Chewing their cud” regurgitate food back into mouth to continue chewing process)

Answer 197

Eat their own feces and try to process it again

Answer 198

1) Megachiroptera: large bats, largest extant species of bats, eat fruit, nectar, pollen, have good vision, do not use echolocation (flying foxes, fruit bats), nectar bat has long tongue, important polinators 2) Microchiroptera: small bats,eat insects, small mammals, fish, 3 species feed on blood, use echolocation, ultrasound produced by larynx (long-eared bats, vampire bats), have smaller eyes

Answer 199

- thermoreceptors on nose - specialized teeth - anti-coagulant “Draculin”

Answer 200

- powered flight has evolved independently three times in vertebrates - bats have much more control over wing shape and curvature than birds or pterosaurs - finger bones flattened and flexible - wings thinner and with touch-sensitive receptors - membrane also stretched between tail and legs - membrane tough and easily repaired - small keel on sternum - flight muscles distributed dorsally and ventrally - fingers 3,4,5 in bats are elongated (finger 2? in birds)

Answer 201

- shallow (seasonal) hypothermia and rest-phase hypothermia (daily torpor) are both shown to some extent in most mammals especially the small ones - deep hypothermia (hibernation or deep torpor) that is induced by low temperatures (ground squirrels, marmots) but with periodic arousals - body temperature can drop almost to ambient

Answer 202

allows the external environment to regulate their internal body temperature

Answer 203

- hibernation=deep torpor | - in small mammals since not energetically advantageous in larger mammals

Answer 204

- activity of sympathetic nervous system reduced | - normal responses to low temperatures suppressed

Answer 205

- non-shivering thermogenesis (in brown fat) - shivering thermogenesis - sometimes with passive warming

Answer 206

- bears do not hibernate - body temperature is at 31-35 degrees celsius - lethargic but alert

Final Exam (Lectures 25 - 35) Flashcards

(237 cards)