Reptiles and Dinosaurs

  1. What are the five extant groups of Reptilia?
    • Aves - birds
    • Squamata - snakes, lizards and worm lizards
    • Crocodilia - crocodiles, alligators, gharials and caiman 
    • Testudines - turtles, tortoises and chelonia
    • Rhyncocephalia - tuatara
  2. What is the binomial name for the tuatara?
    • Sphenodon punctatus 
    • (Least Concern)Image Upload 1
  3. Example of crocodilia species
    • Crocodylus porosus
    • (Saltwater crocodile)
  4. Example of testudine species
    • Chelonia mydas
    • (Green sea turtle)
  5. Example of squamata species
    • Varanus komodoensis
    • (Komodo dragon)
  6. What kind of skull do reptiles have?
    • Diapsid 
    • (except testudines appear to be anapsid - no cranial kinesis)
  7. What group do the Crocodilia and Testudines form?
  8. What group do the Squamata and Rhynchocephalia form?
  9. Which is the most diverse of the extant orders of reptiles?
    • Squamata 
    • Lizards - 6100 spp
    • Snakes - 3400+ spp
  10. What types of dermal structures are found on reptilian skin?
    • Scales - all reptiles
    • Scutes - just turtles
    • Osteoderms - crocodilians lizards and turtles 
    • Filaments (Archosauromorpha)
    • Feathers - pterosaurs (Archosauromorpha)
  11. What are the primary modes of thermoregulation?
    • Heliothermy - heat from the sun
    • Thigmothermy - heat conducted via substrate
    • Kleptothermy - heat gained from endotherms

    (Metabolic - generally restricted to large reptiles)
  12. What are the three main modes of sex determination?
    • Genetic
    • Temperature
    • Parthenogenesis
  13. What are the types of temperature-based sex determination?
    • 1a - males at low temp, females at high temp
    • 1b - males at high temp, females at low temp
    • 2 - males at intermediate temp, females at high AND low temps
  14. What is viviparity and where is it found in the reptiles? Give an example.
    • Live-bearing 
    • Squamates such as Zootoca vivipara (Common lizard)
    • Typically in colder climates
    • Was also found in Icthyosauria and other marine reptiles
  15. What are the features of a reptilian egg?
    • Amniote
    • Leathery
    • Watertight -prevent water loss
    • Breathable - gas exchange
  16. What locomotion styles are exhibited by reptiles?
    • Walking/Running - alternate limbs thrown forward
    • Swimming  - turtles 'fly', undulate sinusoidally ~ e.g. sea snakes
    • Gliding - e.g paradise tree snake
    • Sidewinding 
    • Running on two legs e.g. jesus lizard
  17. What is meant by Biogeography?
    The study of the evolutionary and ecological processes leading to the distribution of organisms
  18. What mechanisms do reptiles disperse by?
    • Own movement
    • Rafting 
    • Via another organism
  19. What is meant by vicariance?
    the geographical separation of a population, typically by a physical barrier such as a mountain range or river, resulting in a pair of closely related species.

    • -separation of continents
    • -formation of mountain ranges
    • -gain/loss of land bridges
    • -island formation and erosion
    • -landslide
  20. What factors tend to influence squamate species richness and diversity?
    • Temperature
    • Moisture
    • Habitat structure
  21. What is island paleoendemism?
    Species that were once widespread but are now restricted to a smaller area.
  22. What types of signalling do reptiles display? Give examples.
    • Visual - e.g. turtles headbob 
    • Chemical - e.g. snake tongue, squamate femoral pores → for marking territory
    • Acoustic - e.g. crocodilians, nocturnal geckos 
    • Tactile  - e.g. testudines → biting, head rubbing etc
  23. What constraints are there on signalling in reptiles?
    • Body size: smaller animals have shorter range
    • Physiology: temperature and energy cost
    • Ecology: Predation risk of signal
  24. Explain the feeding niche of an American Alligator.
    -Resource abundance, patchiness, renewal rate. 
    -Movement within and between patches
    -Home range size
    • Feeding niche example: Ambush predator of vertebrates
    • Resources:  abundance – variable
    • patchiness – variable
    • renewal rate – low
    • Movement:
    • within patch – low
    • between patches – variable
    • Home range size: variable (shifting activity centre)
    • Latin: Alligator mississippiensis
  25. Explain the feeding niche of a Galapagos Marine Iguana 
    -Resource abundance, patchiness, renewal rate. 
    -Movement within and between patches
    -Home range size
    • Feeding niche example: Marine folivore
    • Resources:
    • abundance – high
    • patchiness – low
    • renewal rate – moderate
    • Movement:
    • within patch – low
    • between patches – low
    • Home range size: small
    • Latin: Amblyrhynchus cristatus
  26. Explain the feeding niche of a Western blind snake
    -Resource abundance, patchiness, renewal rate. 
    -Movement within and between patches
    -Home range size
    • Feeding niche example: Ant and termite specialist
    • Resources: abundance – variable
    • patchiness – high
    • renewal rate – variable
    • Movement:
    • within patch – low
    • between patches – variable
    • Home range size: variable
  27. Explain the feeding niche of a Leatherback sea turtle
    -Resource abundance, patchiness, renewal rate. 
    -Movement within and between patches
    -Home range size
    • Feeding niche example: Predator - Jellyfish specialist
    • Resources:
    • abundance – variable
    • patchiness – high
    • renewal rate – low
    • Movement:
    • within patch – low
    • between patches – high
    • Home range size: Extremely large (Nomadic lifestyle)
    • Latin: Dermochelys coriacea
  28. What assumptions can be made about Therapods and Pterosaurs and Ichthyosaurs from fossil evidence?
    Therapods and Pterosaurs: parental care

    Icthyosaurs: viviparous
  29. What is meant by adaptive radiation?
    process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches
  30. What is meant by caudal autonomy? What types are there?
    • Tail Breakage
    • Intravertebral: break along fracture planes on specific vertebrae. Aided by muscle bundles and connective tissues. Voluntary. 
    • Intervertebral: Break between vertebrae. Involuntary. Does not regenerate.
  31. What type of teeth do squamates have?
    • Acrodont - lie in shallow socket, replacement teeth adjacent to active teeth
    • Pleurodont - teeth attached to inner side of the jaw, replacement is continual 
    • Image Upload 2
  32. What are the different ways reptiles can shed?
    • Patches - lizards
    • Entire skin plus eye scale- snakes
    • Individual scutes/cells/ small groups of cells - crocodiles and turtles
  33. What are ISOs and which group has them?
    • Integumentary Sensory Organs
    • Crocodilians 
    • Crocodiles and Gharials have them nearly all over while Alligators and Caiman have them on their face
    • Image Upload 3
  34. What are DCUs and which group has them?
    • Dermal Chromatophore units - pigment containing and light reflecting cells 
    • Squamates - e.g. Chameleons
  35. What mechanisms of water gain are there?
    • Drinking
    • puddles/streams/lakes
    • surface collection on top of salt water
    • transport via specialised cells 
    • Eating
    • Metabolic Water
    • addition of water molecules to hydrogen → oxidation of starch, fat, proteins
    • → fat reserves mean they can survive long time without eating or drinking
  36. What mechanisms of water loss are there?
    • Evaporation 
    • Respiration - intrinsically linked to temperature since they will pant to cool down 
    • Excretion  - semi solid mix of uric acid and faeces via cloaca
    • Salt Glands - causes salt loss
  37. What are thermoregulators?
    Actively adjust behaviour or physiology to affect body temp
  38. What are thermoconformers?
    No active regulation
  39. Why is ectothermy efficient?
    • less energy required overall
    • high conversion rates (energy devoted to growth and repro)
  40. What are "reptiles"?
    • Amniotes 
    • Exclude mammals and birds
  41. What are the two types of island?
    • Continental - connections to mainland may occur with changes in sea level
    • Oceanic - volcanism or reef-uplift
  42. What are the common features/processes of fauna on islands?
    • Gigantism/Dwarfism
    • E.g. glapagos giant tortoises vs. virgin islands dwarf gecko
    • gigantism as a result of food size
    • dwarfism as result of interspecific competition 
    • Adaptive radiation 
    • e.g. Anolis lizard in Caribbean 
    • Island paleoendemism
    • e.g. Galapagos iguanas or tuatara of NZ
  43. How do sea turtle hatchling find their way to the right place?
    • Light - on surface of water
    • Magnetic cues
    • Wave orientation - motion sense
    • → Internal compass
  44. What type of mating systems are there?
    • Scramble Competition 
    • - e.g. red garter snake
    • Mate searching 
    • - solitary reptiles
    • Mate Guarding 
    • - e.g. European Adder 
    • Leks and lekking
    • - are used by males for communal display in breeding season 
    • - e.g. marine iguana 
    • Resource defence
    • - males defend and are of resources to monopolise females
    • - e.g. ornate tree lizards
  45. What are some of the results of sexual selection acting on reptiles?
    • Polyandry and sperm competition 
    • Sexual dimorphism 
    • ♀ typically larger in snakes and turtles
    • ♂ typically larger in crocodilians
    • large variation in lizards
    • Female choice
    • - select mate based on pheremones, display, other fitness cues etc. 
    • Male competitive ability 
    • e.g. leks, resource guarding etc.
  46. What does the movement through a habitat vary based on (in terms of niches).
    • Varies based on diet 
    • (Affects home range size)
  47. What pieces of information does a feeding niche incorporate?
    • Type of prey or feeding strategy (e.g. herbivore, scavenger) 
    • Resources → abundance, patchiness, renewal rate
    • Movement patterns →  within and between patches 
    • Spacing system/home range sizes (e.g. small, variable, nomadic)
  48. What are the different strategies of snakes?
    • Pit organs
    • Constrictors
    • Venom
    • - Elapines ~ short front fangs, neurotoxins 
    • - Vipers ~ hinged fangs, haemotoxins, anticoagulants, necrotising
  49. What are squamate and testudine hearts like?
    • partial left right division 
    • 3 chambered (2 atria and 1 ventricle)
    • 2 aorta
    • →  incomplete separation of oxygenated and deoxygenated blood

    → helps with redirecting blood flow for thermoregulation
  50. What ear bone do squamates have?
    • Stapes
    • (eardrum often reduced or absent)
  51. Which groups are in Acrodonta?
    • Chameleons and Dragons
    • (rest are plurodont?)
  52. What adaptations do the chameleons have?
    • casques/horns/crests
    • colour change
    • tongue projection
    • eyes work independently 
    • locomotion keeps spine straight 
    • feet as grasping pads
  53. What is an adaptation of the iguana for its herbivorous diet?
    • Colon is partitioned to slow passage of food
    • Contains diverse microbiome
  54. How are lizard skulls different to snake skulls - in terms of their prey?
    • Lizard skull adapted to crush and grab prey
    • Snake skull adapted to engulf prey
  55. What are the general defining features of venomous vs non-venomous snakes?
    Image Upload 4
  56. What are some of the adaptations to different lifestyles of snakes?
    Image Upload 5
  57. What is an important feature of crocodilians for their prey choice and aquatic lifestyle?
    • Robust secondary palate
    • → breathing with tip of nose while submerged
    • → protects brain when eating sharp food
  58. What kind of teeth do crocodilians have?
    • Thecodont
    • - rooted in jaw similar to mammals 
    • Polyphyodont → continually shed and replaced
  59. How many eyelids do crocodilians have?
    • 3
    • → nictating membrane cleans eye on land and protects while underwater
  60. In what way is the crocodilian heart specialised?
    • 4 chambered heart - complete division 
    • 2 aortas
    • Valve to allow for mixing of oxygenated/deoxygenated blood and to prevent flow to lungs when underwater for long period of time
  61. What type of sex determination is exhibited by crocodilians?
    • Temperature based
    • 1b→ males at high temp
    • 2 → males at intermediate temp
  62. Which crocodilians teeth fit inside their mouth?
    Alligators and (most) Caiman
  63. What is butt breathing and in which group does it occur?
    How does it work?
    • Cloacal Breathing 
    • in some pleurodires - side-necked turtles

    • Have a pair of bursae lined with papillae → sites of gas exchange
    • Swims with cloaca open & pumps water in and out

    • E.g. Mary River Turtle
    • Image Upload 6
  64. What are the features of male reptiles' reproductive morphology?
    • Squamates: hemipenes
    • Testudines: single penis → large to reach under plastron of female
  65. What method(s) of sex determination do testudines use?
    • Both Genetic Sex Methods
    • → XY or ZW

    • Temperature Based
    • → 1a - males at low
    • → 2 - males at intermediate
  66. What is the name of the group "side necked tutles"?
    • Pleurodira
    • E.g. West African Mud Turtles
    • E.g. Madagascan Big-Headed Turtles
  67. What are some of the factors considered by the IUCN for the red list?
    • Population size
    • Mature individuals capable of reproduction
    • Generation - time taken to breed and reach maturity
    • Reduction in population
  68. What are the red list categories?
    • LC - least concern
    • NT - Near Threatened
    • Threatened - including vulnerable, endangered and critically endangered
    • EW - extinct in the wild
    • EX - extinct

    • DD - data deficient 
    • NE - not evaluated
  69. What classifies as Vulnerable on the red list? (critera and example)
    • Reduction in pop size of >50% over last 10 years/ 3 generations → where cause is known and reversible 
    • Reduction of >30% where cause is unknown 

    Leatherback Turtles
  70. What classifies as Endangered on the red list? (critera and example)
    • Reduction in pop size of >70% over last 10 years/ 3 generations → where cause is known and reversible 
    • Reduction of >50% where cause is unknown 

    • Loggerhead Turtles
    • Tiger Chameleon
  71. What classifies as Critically Endangered on the red list? (critera and example)
    • Reduction in pop size of >90% over last 10 years/ 3 generations → where cause is known and reversible 
    • Reduction of >80% where cause is unknown 

    • Slender-snouted crocodile
    • Galapagos Pink Iguana
  72. What does extinct in the wild mean? Example.
    • Only known to exist in captivity
    • OR naturalised population outside of historical range

    • Christmas Island Blue-tailed Shinning Skink 
    • Christmas Island chained gecko
  73. What does extinct mean? Example
    When there is 'no reasonable doubt' that the last individual has died

    Pinta island giant tortoise
  74. What percentages of reptiles are data deficient and not evaluated?
    • 9.4% DD
    • 42% NE
  75. What are the primary threats to reptiles?
    • Habitat modification and destruction 
    • Invasive species 
    • Disease
    • Pollution 
    • Exploitation → pets and science 
    • Climate Change
  76. What is a particular threat to sea turtles?
    • Loss of critical habitats
    • Need different habitats for different life stages
  77. What problems can invasive/introduced reptiles cause? Give examples.
    • Predation: e.g. brown tree snake on Guam, burmese python in Everglades
    • Competition: leaf-toed gecko vs. house gecko in Barbados
  78. What is parasite spillover?
    The introduction of parasites via invasive species or captive release.
  79. What effects does pollution have on reptiles?
    • Consumption and entangling
    • Toxin bioaccumulation
    • Endocrine disruptors (e.g. causing sex change)
    • Noise pollution
  80. What are some of the problems associated with climate change, especially in reference to reptiles?
    TSD - temp sex determination will give wrong ratios of genders if temp changes

    • Warmer + wetter → higher humidity and flooding
    • Warmer + drier → aridity and forest fires
Card Set
Reptiles and Dinosaurs
Reptiles and Dinos Module