Bio Lecture Test 3

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lledbetter.14
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Bio Lecture Test 3
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2011-11-13 13:58:38
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Vertebrate Bio
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Reptiles, Dinosaurs and Birds
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  1. Names some basic qualities of turtles
    • Similar morphology since the Triassic (250 mya)
    • All turtles have shells
    • All turtles lay eggs
    • All turtles lack parental care
    • Most are very long-lived
    • In many species, sexis determined by nest temperature
    • 13 extant families
    • 300 species
    • Have a beak, not teeth
  2. Describe the shells in the
    Pancake tortoise -
    Box Turtle -
    Pond Turtle -
    Soft-Shelled Turtle -
    Snapping Turtle -
    Tortoise -
    • some hinged plastrons to close shell openings
    • low, streamlined carapace
    • light, reduced ossification
    • small plastron, more agile
    • night domed shell
  3. The main lieages that divided turtles is neck morphology when retracted. Name and describe them.
    • Cryptodires ("hidden neck") - bend neck into S shape. This occurs in most turtle species - however none in Australia
    • Pleurodires ("side neck") - bend neck horizontally. Only found in the Southern hemisphere today.
  4. Describe the Carapace
    • They develop from ribs and vertebrae
    • ribs are external to girdles (unique amony vertebrates)
    • dermal bone of carapace -
    • - 8 plates on dorsal midline fused to neural arches (neural bones)
    • - 8 pairs of costal bones on either side fused to ribs
    • Leatherback sea turtles have carapace made of cartilage with thousands of small bones within
    • In pleurodires, the pelvic girdle is fused to the carapace
  5. Scutes
    • epidermal horny plates that cover the bones of the carapace
    • Soft shell turtles lack scutes and ossified peripheral bones
  6. Discuss the Plastron
    • Some of the plastron derived from clavicle and interclavicle
    • some tortoises and box turtles have hinged plastrons so that the shell can be closed
  7. Discuss Turtle Vertebrae
    • Only 8 elongated trunk vertebrae
    • Centra are fused
  8. Turtles cannont breathe through expansion of rib care like other reptiles. Describe how they do breathe.
    • Contraction of posterior muscules
    • - transverse abdominus
    • - reduces visceral cavity, pushes air out
    • - (similar to mammalian diaphragm)
    • Contraction of abdomial oblique (pelvic) and serratus (pectroral) i
    • -increase visceral cavity, expands lungs
    • Aquatic turtles exchange oxygen and Co2 in water through pharynx and/or cloaca
  9. Describe Nesting Behavior of turtles
    • Oviparous (lay eggs)
    • shells are either soft and flexible or hard
    • Development takes 40 - 60 days
    • some diapause over winter (arrested development)
  10. What are the environmental effects on turtle eggs
    • Temperature, humidity, and oxygen can affect development
    • in many species, sex is determined by egg temperature with 3 -4 degrees C (same nest can vary)
    • higher temp produces larger sex (in turtles, usually female)
    • selection - fitness of a sex should be higest at temperature produced
  11. Discuss Hatchlings of turtles
    • hatchlings are independent in some species (sea turtles), eggs are buried deep in sand hatchlings hatch and dig out together high predation rate as many nest usually hatch at once
    • Hatchlings navigate by
    • -light - lighest sky at night is over ocean
    • -Wave direction - initially swim against the waves
    • - magentism - tells turtles not only direction by latitude - how to avoid going to far north or south
  12. Breeding and Migration of turtles
    • For pond turtles, local knowledge is probably enough
    • Sea turtles can feed and nest throusands of miles apart
    • -tutles mate offshore, then females go ashore to lay eggs
    • -Return to natal beach to nest
    • -Chemosensory cues (smell increases as get closer
  13. Conservation of tutles
    • Large tortoises and sea turtles most at risk
    • - long life spans plus threatened habitats
    • Large tortoises live on small uninhabited (by humans) islands
    • - little competition for resources, predation
    • Turtles for food - probably about 12 million yearly in China
    • (also eaten in USA as turtle soup, much less common now)
    • Pet trade - smuggled exotics from madgascar, or within the USA
    • - endangered turtles more expensive
    • Road Kill
    • Loss of Habitat
    • target pratice/other unnecessary deaths
  14. Stupendemys
    • South America
    • Pleciocene
    • 5 - 6 mya
    • carapace more than 2 m long
  15. Mata Mata - long necked "snake neck" turtles
    • Family Chelidae
    • Up to 40 cm long
    • South American Freshwater
    • Skin folds for camouflage, sensing motion
    • Glups food
  16. Leatherback Sea Turtle
    • Family Dermochelyidae
    • Skell reduced to bony platelets in connective tissue
    • more than 2 m long, 600 kg
    • wide geographic distribution
    • dive up to 1200 m deep
  17. Turtles
    • Class - Reptilia
    • Order - Testudines
  18. Turtles in Culture
    • Symbols of longevity, patience and wisdom
    • Important to creation myths (World Turtle)
  19. Family Testudinidae
    • Tortoises - land-dwelling turtles
    • lack of webbing on toes
    • short legs
    • usually herbivorous
    • warm climates
    • only 4 rear toes
  20. Aldabra Giant Tortoise
    • Family Testudinidae
    • Dipsochelys dussunieri
    • variety of habitats - forest, swamp, and beach
    • tortoise turf - coevolved plant species mix eaten by tortoises
    • up to 150 cm, 250 kg
    • crepuscular
  21. crepuscular
    active at dawn and dusk
  22. Red-eared slider
    • Family Emydidae (box and pond turtles)
    • Trachemys scripta
    • Widespread, new world northern hemisphere
    • quiet, mud-bottomed water, good basking spots
    • sleep underwater
    • up to 30 cm
  23. Box turtle
    • Family Emydidae (box and pond turtles)
    • Terrapene carolina
    • North America
    • often near ponds, but also woods and meadows
    • hinged plastron
    • up to 18 cm
    • small home range of 250 m diameter
    • omnivorous
  24. Alligator Snapping Turtle
    • Family Chelydridae (3 species, including 2 snapping turtles)
    • Macrochelys temminckii
    • large heads, limbs cannot be fully retracted
    • around large bodies of water in southeastern/middle US fresh water
    • 11 -13 years for maturity
    • worm-like protrusion on tongue to lure prey
  25. Lepidosaurs
    • Includes Tuatara, Lizards, Snakes
    • a group with Class Reptilia
    • Largest group of reptiles
    • 4800 lizard species, 2900 snake species, 2 tuatara species
    • usually terrestrial and tetrapod
    • scaly waterproof skin
    • -outer layer shed at intervals
    • Sister taxa of archosaurs (crocodilians and birds)
    • Two sister groups with Lepidosaurs
    • 1. Lizards and snakes = Order Squamata
    • - snake loss of limbs = derived trait
    • 2. Tuatara = Order Rhynchocephalia
    • Major groups had evolved by end of the Jurassic (approx. 150 mya)
    • Two major lineages:
    • 1. Suborder Iguania includes iguana, collared lizard, chameleons, anoles
    • 2.Suborder Scleroglossans skinks and gekkos, amphisbaenians (burrowing lizards), serpentes (snakes)
    • Tuatara is Maori for "spines on back"
  26. Discuss determinate growth in Lizards
    • also found in birds and mammals
    • in contrast to turtles and crocodilians
    • Growth occurs until epiphyses of bones ossify
    • A derived trait
    • - may be adaptation to diet of small prey
  27. Basic facts about Lizards
    • most adult lizards weight less than 20 grams
    • most adult lizards are insectivores
    • - some are extremely specialized
    • --ex. horned lizards feed solely on ants
    • frequently diurnal, but some (like geckos) are usually nocturnal
    • many species are arboreal
  28. Easten Fence Lizard
    • Family Phrynosomatidae (Iguania)
    • Sceloporus undulatus
    • most of eastern USA
    • eggs double in size after being laid
    • active during the day
    • males exhibit head bobbing & push up territorial display
    • eat mostly arthropods, inc ants
  29. Anolis Lizard
    • Genus Anolis, various species
    • complex territorial and mating displays
  30. Iguana
    • Family Iguanidae
    • herbivorous like most large lizards
    • Green Iguana (Iguana iguana) native to central and S America, invasive to Florida, Hawaii
  31. Marine Iguana
    • Family Iguanidae (Iguana)
    • Amblyrhynchus cristatus
    • Galapagos islands
    • probably arrived 10 mya
    • unique diving iguana up to 10m
    • aggressive at low temps
    • black to absorb heat
    • at risk from cats and dogs
    • nasal gland to excrete salt crystals
  32. Tuatara
    • Order Rhynchocephalia
    • sister taxa to squamata (~ 200 mya split)
    • diverse during Mesozoic
    • only 2 species remain
    • first protected reptile species (1895)
    • 1 species lives on 30 small islands off new Zealand,
    • - to be re-established in New Zealand
    • common tuatara, Sphenodon punctatus
    • 1 species lives on 1 island,
    • -being re-established on several more
    • Brothers Island tuatara Sphenodon guntheri
    • lack external tympanum of lizards
    • -(no eardrum, no hole)
    • lack paired, evertable hemipenes (vs. squamates)
    • --paired reproductive organ usually inside vent
    • nocturnal
    • can support low active body temps
    • bask during day
    • 60 cm long
    • diet: mostly invertebrate, some seabirds
    • nest in burrows with seabirds
    • arthropods attracted by bird refuse
    • males and females are territorial
    • - vocal & behavioral displays
    • - displays: throat puffing, stiffen spines open mouth and snap jaws
  33. Cranial Features of the Tuatara
    • enlarged row of teeth along palatine on maxilla side
    • --double row on upper jaw (like some snakes)
    • acrodont teeth: fused to top edge of jaw, sharp bone projection, no sockets (like many lizards)
    • heterodont teeth: more than one type of tooth
  34. Discuss the Parietal Eye of the Tuatara
    • "third eye" on top of skull
    • cornea, lens, retina
    • nerves to brain degenerated
    • visible in hatchlings, later covered by scales
    • covers pineal gland (melatonin)
    • chronobiology:
    • - circadian rhythms (sleep/wake)
    • seasonal rhythms
  35. Tuatara Conservation
    • in Holocene (10K ya to present) widely spread in New Zealand
    • loss of habitat due to Maori 1000 ya, then European arrival rat & dogs as predators
    • trampled by cattle
    • mature at 12 -15 years,
    • - females only reproduce every 3-4 years
  36. Amphisbaenians
    • Order Squamata
    • Suborder Scleroglossans
    • several families of worm lizards within this suborder
    • specialized
    • fossorial = diggers
    • usually legless, 3 species have forelimbs
    • highly modified skull
    • bodies with annuli (rings)
    • Amphi (double)
    • baen (walk)
    • skin is loose around body
    • can back up in tunnels as easily as move forward
    • loss of legs independent of snake limb loss
    • remnant of pectoral and pelvic girdles
    • median (middle) tooth in upper jaw
    • distribution: tropics, southern hemisphere
  37. Mexican Mole Lizard
    • Family: Bipediae
    • Bipes biporus
  38. Anoles
    • Class Reptilia
    • Lizards and snakes = Order Squamata
    • Suborder Iguania
    • Genus Anolis
    • inhabitat many islands of the Caribbean,
    • - including Hispaniola, Puerto Rico, Jamaica and Cuba
    • independently colonized islands over 25 mya
    • evolved multiple species on each island
    • display head bobbing and dewlap flapping
    • females prefer displays of own species
    • - used for identifying correct species in mating?
  39. Ecomorphology
    • Ecomorphology = study of relationship between ecology and morphology
    • Ecomorph = ecologically equivalent species similar environment may lead to similar forms examples of convergent evolution
    • Ecomorphs based on preferred microhabitat
    • - distantly related species may physically resemble each other more than closely related species
    • Traits that vary by ecomorph include
    • body size and shape
    • head size
    • limb length
    • density of toe lamellae (toe pads)
    • diet
    • selection experiments by moving anoles to new habitats
  40. Covergent Evolution
    • organisms that are not closely related evolve on similar evolutionary lines
    • due to response to similar adaptive pressures
  41. Anole Ecomorphs
    • trunk-ground have longest legs for sprinting and jumping
    • twig morph is small and slender
    • grass-bush ecomorph have slender bodies but long tarsi and metatarsi for grasping narrow surfaces
  42. Snakes
    • Class Reptilia
    • Order Squamata
    • Suborder Serpentes
    • 2,900 species worldwide (except Anatarctica)
    • 10 cm – 10 m
    • loss of limbs is derived trait
    • None retain pectoral girdle
    • Some retain part of pelvic girdle = vestigial limbs
    • Probably originally evolved from burrowing lizards with reduced eyes
    • forked tongue for chemosensation (Jacobson’s organ)
    • Earliest known snakes from Cretaceous 112 mya
    • most snakes also have:
    • lost pelvic girdle
    • single carotid artery
    • very moveable skull
    • reduced or absent left lung
    • right kidney anterior to left kidney
  43. Titanoboa cerrejonesis
    • largest known snake ever
    • 60 mya
    • 42 feet long (12 m)
  44. Snake Motion
    • 1.Lateral undulation: curves can be very fast
    • 2.Rectilinear locomotion: alternate sections lift off the ground waves of contraction slow but in a straight line
    • 3. Concertina locomotion: accordion-like used in burrows
    • 4. Sidewinding: body loops swung forward primarily in desert snakes where substrate is slippery
  45. Komodo Dragon
    • Scleroglossa
    • the largest monitor lizard
    • infectious bite
  46. Parthenogenesis
    • Greek for "virgin birth"
    • The ability of a female to produce offspring withoutmale genetic contribution (fertilization)
    • Most commonly known in squamates
    • Evidence in sharks as well
    • Probably more common than known
    • genetic testing in non-sexually dimorphic species
    • Offspring identical genetically to mother
    • Every individual in a parthenogenetic species can reproduce = double the reproductive output of a bisexual species useful in areas of severe habitat loss/disruption
    • Long-term problem: lack of recombination, lower rate of adaptation
    • Occasional sexual reproduction would help
  47. Whiptail Lizards
    • Genus Cnemidophorus
    • includes many parthenogenetic species usually result from hybridization (interspecies breeding)
    • clonal population = genetically identical
  48. Desert Ecotherms
    • Low densities of plants -> low densities of insects
    • large differences between night and day temperatures
    • temperature extremes moderated underground
    • burrowing as an adaptation
    • Most desert vertebrates are small (low energy in system)
    • tortoises are the largest
    • - shallow summer burrows for day
    • - deep winter burrows for hibernation
  49. Chuckwalla
    • Order Squamata
    • Desert Iguanine
    • nasal salt gland for excretion
    • obtain water from plants
    • water can also be produced as a metabolic by-product (metabolic water)
    • in winter, hibernate in rock crevaces
    • in spring
    • - bask much of day
    • - eat annual plants (new growth)
    • - early spring annual plants have lots of water
    • in summer
    • - annual plants withered, eating perennial plants (less water, tougher)
    • - weight & water loss active only once a day
    • - stop eating in July—only bask briefly every 2 or 3 days, hide in crevices otherwise
    • by October, weight is 37% less than in early spring
    • combat water loss in summer, early fall:
    • - stop eating, become inactive -> slower breathing -> less water loss through respiration
    • also less loss through excrement
    • rock crevices have higher humidity
  50. Desert Amphibains
    • careful use of microhabitats (small locations within the habitat with a slightly more favorable condition)
    • most time spend underground
    • temporary aquatic environments during rainy season
    • (puddles & pools)
    • rapid amphibian development
  51. Spadefoot Toad
    • underground burrow September – July
    • at end of rainy season (Sept.), burrow is more moist than toad, -> water gradient into toad
    • when soil and toad are = in water, toad stops excreting urine and retains urea,
    • increasing osmolality of toad -> can absorb water from almost dry soil
    • egg-to-metamorphasis in under 3 weeks
  52. Freezing Ecotherms
    • endotherms (mammals & birds) produce metabolic heat & insulate
    • ectotherms have two strategies:
    • - synthesize antifreeze
    • - have freeze-damage resistant tissues
    • increased osmolal concentrations lowers freezing point
  53. Freezing Ecotherms - Fish
    • supercooling: body water remains unfrozen below freezing point
    • crystallization of water molecules avoided by lack of nucleating agents that hold molecules in structure
    • antifreeze compounds: found in vertebrates, invertebrates, plants
    • also prevent water molecules from orienting to crystal structure often glycoproteins
  54. Freezing Ecotherms - Reptiles
    • supercooling, osmolality that resists freezing
    • some turtles have a skin barrier that resists ice crystals
    • inc. lipid layer under a layer of keratin
  55. Freezing Ecotherms - Frogs
    • 1)buries deeply in mud or hiberates to avoid freezing temps
    • 2) freeze toleration in tissues
    • can tolerate freezing of extracellular fluids
    • molecules to resist intracellular freezing
    • tolerate ice content of 34 -48 % glucose or glycerol in cells to avoid freezing anaerobic metabolism in cells
  56. Body size and Shape of Ectotherms
    • ectothermic metabolism is low compared to endothermic
    • require less energy
    • most ectotherms are small
    • endothermy is expensive at small sizes, ectothermy is not
    • high surface area/mass ratios means more heat exchange
    • - dorso-ventral flattening
    • less than 10% of endothermic energy goes to growth/biomass rest is to maintain temperatures
    • 30 -90% of ectothermic energy goes to growth/biomass
  57. The Mesozoic Era
    • 251- 65.5 mya
    • Triassic, Jurassic, and Cretaceous Periods
    • 240 mya - Pangaea
    • 120 mya - Laurasia and Gondwana
    • Diapsids include - dinosaurs, crocodiles and birds
    • - also extinct pterosaurs "winged lizards", ichthyosaurs "fish lizards", plesiosaurs "nearly a lizard", placodonts "tablet teeth"(marine reptile (iguana -like))
    • Forms evolved multiple times
    • - ex. several different lineages of armored quadrupeds like stegasaurs
    • difficult to resolve evoltuionary relationships
  58. Discuss the Triassic Period (not including vertebrates)
    • 251 - 200 mya
    • hot and dry, little glaciation even at poles
    • adaptive radiation following the Permian Extinctions
    • modern corals
    • ferns, gymnosperms (conifers, cycads, gingkos)
    • shift from ferns to conifers in late Triassic -> changes in tetrapods
    • very low atmospheric oxygen = hypoxic
  59. Vertebrates of the Traissic Period
    • Archosaur reptiles
    • - many extinct dinosaurs
    • - living examples are birds and crocodilians
    • herbivorous vertebrates up to about 1000 kg (2200 lbs)
    • mostly small-bodied
    • almost no arboreal vertebrates
    • pterosaurs "winged lizards" —first flying vertebrates!
    • first sphenodontids (related to tuatara)
    • first mammmals
    • first dinosaurs, turtles, crocodiles
    • extinction of some mammal-like reptiles (tidal ventilation)
    • radiation of archosaurs (related to crocs and birds, some unidirectional airflow probable)
  60. Jurassic Period (200 - 145 mya)
    • The Age of Reptiles—rise of dinosaurs
    • Fish and marine reptiles are the major vertebrates
    • - ichthyosaurs "fish lizard", plesiosaurs "nearly a lizard", crocodiles
    • radiation of plankton (marine animals’ diet)
    • Archosaurs remain important
    • - first salamanders & caecilians
    • lizards and modern amphibians
    • earliest bird (Archaeopteryx)
    • giant herbivorous sauropods (over 50,000 kg)
    • how did plants sustain them?
    • - high C02 = high plant growth
    • By end of period, all modern tetrapod groups have evolved
    • - inc. frogs, salamanders, lizards, snakes, turtles, crocodiles, birds, mammals
    • even though dinosaurs are the most famous & dominant groups of this period
  61. Angiosperm Origins - 145 - 208 mya
    • In context: 145 mya is the beginning of the Cretaceous Period dinosaurs are the dominant tetrapods (= 4 footed vertebrates)
    • small mammals, birds, and pterosaurs. First snakes.
    • diversification of insects: ants, bees, termites appear
    • CO-EVOLUTION
  62. Cretaceous Period (145 - 65 mya)
    • warm climate
    • angiosperms, birds, and mammals radiate
    • ends with the K-T extinction, one of the biggest extinction events
    • largest trees still conifers
    • grasses evolve by end of period, but not extensive coverage (no grassy prairies or fields)
    • evolution of mammals by mid-Cretaceous, have placental, marsupial & monotremes
  63. Mesozoic Climate
    • No polar ice caps at all
    • moist poles, drier at equator
    • no tropical rainforests
    • cooling episode at end of Cretaceous
  64. Mesozoic Extinction
    • Smaller extinction event at end of Triassic
    • - meteor?
    • - break up of Pangaea?
    • - replaced by new groups like dinosaurs
    • Major extinction event at K-T boundary end of Cretaceous
    • not as major as the Permian extinction
    • dinosaur fauna in decline for some million years previous
    • drop in sea levels concurrent with extinction
    • climate change from mild (Mesozoic) to cool (Cenozoic)
    • mass extinction in a variety of fauna, but not all taxa =differential selection
    • iridium layer at KT boundary
  65. K-T Extinction
    • Hypotheses:
    • - Asteroid collision?
    • - Volcano activity?
    • - Dinosaur plague?
    • - Result of Plate Techtonics?
    • - Mammals ate everything?
    • extinction of 40% of tetrapod families
    • inc non-avian dinosaurs,
    • all flying reptiles (pterosaurs)
    • marine reptiles (ichthyosaurs, plesiosaurs, etc)
    • additional extinctions among mammals, birds, plants, marine invertebrates
    • debate: how sudden?
    • dinosaur fauna in decline for some million years previous
    • strong evidence for asterioid hitting Yucatan in Mexico
    • - iridium in sediments iridium
    • - rare on surface, more common extraterrestrially
    • dust clouds have similar impact as volcanic eruptions at Permian extinction
    • Deccan Traps: major volcanic eruption, this time in India
    • patterns do not equal process
    • why do we see patterns?
    • most verts larger than 10 Kg became extinct
    • better reproductive capabilities?
    • modern amphibians are very sensitive to environment --anura, urodela, and gymnophiona all survived
    • **Fossil evidence doesn’t always supply what is needed to answer the question**
  66. Mesozic Extinction Current Hypotheses
    • Asteriod Collision off Yucatan in Mexico
    • - Impact Crater of right size and time
    • - Iridium layer (rare on Earth, common on asteroid, deep in Earth)
    • - Melted Rock at KT boundary
    • - Shocked quartz (fractured crystals) at KT boundary
    • Deccan Traps: major volcanic eruption, this time in India
    • - Deccan Traps (India) cover 200,000square miles
    • - Iridium and shocked quartz also possible in this scenario
    • note: India was moving toward Asia at
    • -about 15 cm/year
    • --major techtonic activity
    • --touches Asia at about 55-50 mya
    • (currently moving at 6 cm/year)
    • dust clouds would have similar impact as volcanic eruptions at Permian extinction
    • ******Correlation ≠ Causation*******
  67. Collision Event is the most accepted (but not only) hypothesis today.
    • 180 km (110 mi) diameter crater
    • 10 km (6 mi) diameter asteroid impact
    • 2,000,000 greater than largest nuclear bomb
  68. Parallel Evolution of Wings
    • Parallel Evolution of Digits
    • Same 5 digits different arrangement
    • Membrane off elongated 4th, thumb and first 3 free
    • membrane all but thumb
    • fused 2 and 3
  69. History of Paleontology in the United States
    • The Bone Wars
    • Edward Cope (National Academy/U Penn) vs. Othniel Marsh (Yale)
    • backstabbing, sabotage, and discovery
  70. The Bone Wars
    • began in late 1960’s
    • context: Darwin’s Origin of Species published in 1858
    • completion of transcontinental railroad in 1860’s
    • competition to excavate and NAME unique species
    • in the American West
    • support for evolution
    • Smithsonian (Washington DC) has top dinosaur collection (Marsh)
    • Cope has record for most scientific papers published --1,400!
    • Marsh named 80 new dinosaurs to Cope’s 56
    • Specimens from both collections described and studied long after deaths
  71. Dinosaurs Discoverd by Marsh and Cope
    • Marsh -
    • - Triceratops
    • - Allosaurus
    • - Apatosaurus
    • - Stegasaurus
    • Cope -
    • - Lystrosaurus
    • - Elasmosaurus
  72. Two main groups of derived Diaspids
    • 1.Archosauromorpha "ruling lizard form" crocodiles, birds, dinosaurs, pterosaurs
    • 2.Lepidosauromorpha "scaled lizard form" tuatara, squamata, *plesiosaurs, *placodonts, *ichthyosaurs
  73. Archosaurs
    • crocodilians
    • secondary palate separates nasal passage from mouth
    • --ability to breathe with just nostrils exposed
    • most similar extant archosaurs to ancient forms
    • 23 extant species
    • mainly tropical
    • semi-aquatic, salt and fresh water
    • depressor mandibulae is short and lacks power (opens jaw)
    • levator mandibulae is very powerful—can crush turtles (closes jaw)
    • caudofemoral muscle
    • origin: base of tail
    • insertion: 4th trochanter
  74. What do Crocodilians and Birds tell us about dinosaurs
    • parental care and vocalizations known in both birds and crocodiles
    • hatchling crocodilians call to be dug out of nests -> probably in dinosaurs too
  75. What are the two independently evolved clades?
    • Ornithischia: "bird hipped"
    • -elongated ilium to anterior
    • Saurischia "lizard hipped"
    • - elongated pubis and ischium , pubis rotated to anterior
    • - Selection for increased locomotion
    • - legs under body, bipedalism
  76. Evolution of bipedalism allowed for what specilazations
    • Specialization of forelimbs for
    • - grabbing prey
    • - flying (evolved twice - birds and pterosaurs)
  77. Ornithischian Dinosaurs
    • herbivorous
    • many had beaks rather than teeth
    • armored quadrupeds
    • evidence of parental care
    • -groups of hatchlings fossilized together
    • - fossilized mother protecting eggs
    • skulls suggest vocalization
    • ex. Stegasaurus
    • ex. first recognized dinosaur Iguanodon
    • ex. duck-billed dinosaurs
  78. Saurischian Dinosaurs
    • 1.Sauropodomorpha "reptile foot form"
    • - mostly quadrupedal herbivores
    • - includes giant quadrupedal herbivores like Diplodocus
    • - largest may be over 30 m and 40,000 kg (elephant = 5 m & 5,000 kg)
    • - possible herd behavior
    • -- evidence from tracks
    • 2.Theropoda "beast feet"
    • - mostly bipedal carnivores
    • - may have attacked with jaws (like T. rex), hind limb or forelimb
  79. Bird Origins
    • evolved from therapods
    • furcula (wishbone) evolved in therapods from clavicles
    • Birds evolved during the Late Jurassic -> coexisted with pterosaurs
    • Traditional taxonomy
    • - Class Reptilia
    • - Class Aves
    • - but—evolutionarily, Aves are part of Reptilia
  80. Common Traits between Birds and Theropods
    • hollow bones with air spaces (pneumatic)
    • S-shaped neck
    • tridactyl foot—three toes forward, one back
    • digitigrade posture = walking on toes
  81. Trait Evolution in Birds
    • birds are very derived (modified) reptiles
    • wrists of therapod rotate sideways -> grasp prey
    • - in birds, used to direct air over feathers for flight
    • orientation of glenoid fossa in therapods -> freer arm movement
    • - in birds, used for wing flapping
    • feathers
    • - evolved in dinosaurs
    • - evidence for hollow shafts of beta keratin
    • evolved pre-flight-- purpose?
    • - insulation and/or display
  82. Class Aves
    • 9,600 Species
    • mechanics of flight shape bird morphology
    • flightless birds are secondarily flightless (evolved loss of trait)
    • most birds are diurnal = awake during the day
    • most birds have excellent vision
  83. Archaeopteryx
    • theropod dinosaur
    • transitional fossil
    • 150 mya (Jurassic)
    • jaws with teeth
    • 3 fingers with claws
    • long bony tail
    • feathers
  84. Bird Evolution from Therapods
    • Center of Gravity shifted forward toward wings
    • shortened bony part of tail
    • pygostyle = fused posterior tail vertebrae
    • beak with no teeth
    • coracoid bones support pectoral muscles smaller foot claws for perching large sternum = keel
    • wrist that bends backward
  85. Bird Evolutionary History
    • modern birds diversified during Cretaceous ~ 90 mya
    • few fossils = few species?
    • by late Cretaceous many ecomorphs evolved
    • inc. wading, perching, swimming, flightless
  86. Bird Structures
    • specialization for feeding and locomotion
    • body plan evolutionarily conserved for flight
    • upper limit to body mass for flight
    • long runs for takeoff
  87. Discuss Feathers
    • develop from follicles in skin
    • 90% beta keratin (related to keratin in reptile scales)
    • Structures
    • Pennaceous Section Vane
    • - sheetlike, smooth part
    • - tightly formed by hooks on barbules
    • - sheds water, protect down
    • - directs air
    • Rachis
    • Barb
    • - Barbules: branch off from barbs and hook to neighbors
    • Downy Section
    • - Downy or plumulaceous section: Fluffy, hookless part at base
    • - insulation
    • Calamus
  88. Preening
    behavior in which bird smooths out barbs
  89. Contour Feathers
    • includes remiges (wing) and rectrices (tail)
    • stiff, mainly pennaceous
    • used in flight –steering etc
  90. Semiplumes
    • intermediate between contour and down
    • large rachis but entirely plumulaceous
    • mostly insulation
  91. Down Feathers
    • plumulaceous only
    • rachis absent or tiny
    • insulation
  92. Bristles
    • Highly Specialized
    • Usually around eyes or mouth
    • block particulate matter
    • may aid tactile sense
  93. Filoplumes
    • Fine, hairlike, few barbs at tip
    • sensory structures underlie contour feathers
    • very rarely used in display
  94. Bird Skeleton
    • Air - filled bones (pneumatic)
    • hindlimbs relatively heavier than mammals
    • very light skull
    • elongated pelvic girdle
    • synsacrum: fused vertebrae, firmly attached to ischium and illium
    • tail: 5 vertebrate plus fused pygostyle
    • pelvic girdle + inflexible thoracic vertebrae + pygostyle = rigid vertebral column
    • neck (cervical vertebrae) usually flexible
    • keel on sternum for attachment of flight muscles
    • fused clavicles -> furcula
    • coracoid supports scapula
    • joint of ankle within tarsus
    • metatarsals fused with distal tarsals -> tarsometatarsus
    • tibia fused with proximal tarsals -> tibiotarsus
  95. Bird Muscles
    • pectoral muscles may be 20% of body mass
    • need to maximum gas exchange:
    • - large hearts, high blood flow, through-flow lungs, crosscurrent exchange
    • need to dissipate heat from muscles
    • hind limb muscles can also be strong
    • - swimmers like ducks
    • - hawks & owls catch prey with feet
    • - terrestrial or flightless birds
  96. Wings
    • function for lift and propulsion
    • change of shape, area, and orientation in wings
    • ability to maneuver
    • Supracoracoideus - raises wing
    • pectoralis - lowers wing
  97. Avain muscles of the pectoral girdle
    • Tendon of Supracoracoideus
    • supracoracoideus - raises wing
    • pectoralis - lowers wing
    • keel of sternum
    • coracoid
    • humerus
  98. Dynamic Soaring
    • long, narrow, flat wings
    • needs strong persistent winds
    • certain seabirds (ex. albatross)
    • uses wind gradient
    • (slower near water)
  99. Elliptical Wings
    • birds that fly around objects, like woodland birds fast flapping, slow flight
    • good maneuverability
    • ex. pheasant
  100. High Aspect Ratio
    • fast flight
    • usually long migrations, aerial foraging, diving
    • ex. swifts, barn swallows
  101. High - Lift Wing
    • static soaring
    • maneuverability uses rising air masses
    • large birds
    • ex. vultures, eagles
  102. Bird Migration
    • V-shaped formation
    • flying in the wake of other birds saves energy
  103. Hindlimb Specilizations
    • Anisodactyl
    • Zygodactyl
    • Heterodactyl
  104. Perching
    • Foot tendons lock so bird doesn’t relax grip & fall off branch
    • plantar tendons tighten when legs bend
    • sitting bird can safely sleep
    • 1. ideally 4 free medium-length toes— 3 toes forward and one backward = anisodactyl foot most passerine (perching birds) ex. robin, blue jay
    • 2. 2 toes forward and 2 backward = zygodactylous foot
    • ex. parrots and woodpeckers (vertical perching)
  105. Running, Hopping and Walking in Birds
    • hopping: mainly perching arboreal birds
    • - many passerines ( = perching birds) are limited to hopping
    • walking: alternate feet touch ground
    • running: both feet off ground at same time for part of step
    • - usually long legs, small feet
    • - often reduction in toe #
    • - ostrich has 2 = didactyl
    • -rhea has 3 = tridactyl
  106. Climbing
    • use feet, sometimes also beaks, tails and wings
    • ex. woodpecker uses tail for support
  107. Surface Swimming
    • webbed feet (ex. ducks)
    • lobed toes (ex. grebe)
    • wide body for stability
    • dense plumage for insulation & bouyancy
    • large preen gland for waterproofing oil
    • water resistant feathers
  108. Diving and Underwater Swimming
    • through specialization of hindlimb (some loons)
    • wings (penguins -> flightless)
  109. The blue-footed booby's mating dance
    Uses blue feet to attract mates

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