Reptiles_ Birds and Mammals

Document Sample
Reptiles_ Birds and Mammals Powered By Docstoc
					Reptiles, Birds and Mammals

   Our scaly, feathered and hairy
               friends!
    3 Key Adaptations for Life on Land
• 1. Amniotic Egg
• 2. Internal Fertilization
• 3. Water-tight skin
• An amniotic egg is a waterproof egg with a shell.
• It is named for a particular membrane called the
  amnion.
• The amnion protects the embryo from drying out
  and surround a fluid filled cavity that cushions it.
               Key Adaptations
• The other membranes formed during development
  of the embryo function in gas exchange, waste
  removal and supplying nutrients.
• The amniotic egg makes it possible to lay an egg on
  land without needing to return to the water like an
  amphibian.
                 Key Adaptations
• In internal fertilization, the male deposits sperm within the
  female’s body.
• The sperm then swims inside the reproductive tube towards
  the egg.
• This allows for reproduction to take place outside of water.
• Amniotes have a water-tight skin enriched with a
  waterproofing protein called keratin.
• The keratinized skin prevents dehydration.
            Key Adaptations
• Reptile skin has scales which are hard,
  overlapping structures made of keratin.
• Birds have feathers made of keratin.
• Mammals have hair, nails and horns made of
  keratin.
                Vocabulary
• Ectotherms-main source of body heat is the
  environment-cold-blooded
• Endotherms-body heat generated internally
  by cell metabolism, warm-blooded
               History of Reptiles
• The oldest reptile fossils have been found in rocks dating from
  the Carboniferous period about 300 mya.
• Reptiles diversified in the Mesozoic era.
• At that time, dinosaurs occupied every habitat and ecological
  role.
• Some were very quick and agile indicating that they might
  have been endotherms.

• Some fossils of dinosaurs have been found with feathers.

• Dinosaurs became extinct 65 mya from a massive collision
  with a comet or asteroid.
Snakes
Lizards
Crocodilians




               Crocodile




                 Alligator
Crocodilians


               Caiman




                  Gavial
                   Tuaturas
• Rare, old species
• Different structures than lizards, vestigial third
  eye and slowest metabolism in reptile class
• Endangered
• Live only on islands near Australia and New
  Zealand
Tuatara-living fossil
                                                  Reptiles




 Turtles and                     Lizards and
                                                                Crocodilians                 Tuataras
  Tortoises                         snakes




                                                                 Alligators
 Hard shell                  Can be legless or                                                 Rare
                                                                   Crocs
Made of scutes                 Have limbs                                                   endangered
                                                                 caimans




                                                                                                         Different physical
                 Longest lived                 Snakes evolved                  Related to
                                                                                                          Characteristics
                   reptiles                     From lizards                   dinosaurs
                                                                                                            Than lizards
             History of Birds
• Molecular and fossil evidence indicated birds
  and crocodilians are more closely related to
  dinosaurs than any other reptiles.

• Feathers-modified scales made of keratin used
  for flight and insulation
                        Birds
• Birds have a system of branching air sacs that
  function with their lungs in respiration.
• The air sac system helps supply the high levels of
  oxygen that support a high rate of metabolism.


• Air sacs also reduce the overall body weight of the
  bird.
• Bird bones are honeycombed and mostly hollow but
  are still structurally strong.
    Bird’s Adaptations to Decrease Body
                   Weight
•   1.   Air sac system
•   2.   Honeycombed bones
•   3.   Absence of many internal organs
•   4.   Absence of teeth
                        Birds
• Gizzard- muscular organ often containing small
  stones that grind seeds and other food
• Crop- sac like organ used for temporarily storing food
• 4 chambered heart is efficient by keeping oxygen rich
  blood completely separate from the oxygen poor
  blood.
               Origin of Birds
• Many paleontologists agree the ancestor of
  birds was a small, feathered dinosaur.
• A famous bird fossil, Archaeopteryx lived 150
  mya.
• It had a mixture of bird and reptilian features.
Archaeopteryx
                  Flying Styles
• Rapid altitude changes-finches, cardinals
• Soar and glide on air currents-falcons and albatrosses
• Flap or buzz quickly and can hover or go backwards-
  hummingbirds
• Flightless swimming/diving birds-penguins
• Flightless running birds-ostriches, emus
           Beak Adaptations
• Made of keratin
• Modified to the food source
• Toothless and cannot chew
               Foot Structure
•   Perching-songbirds
•   Grasping-woodpeckers, nuthatches
•   Raptors-eagles, hawks
•   Swimming-ducks, geese
Perching Birds
Swimming Birds
Raptors
                          Birds




Perching      grasping            raptors   swimming




Cardinals                         Eagles     Duck
            woodpeckers
songbirds                         hawks      geese
         Behavioral Adaptations
•   Complex courtship behaviors
•   Complex song communications
•   Caring for offspring
•   Nest building
            Origin of Mammals
• The oldest fossils of mammals date back about 200 mya to
  early Mesozoic era.
• Fossil evidence indicates mammals evolved from reptiles
  called therapsids.
• Early mammals coexisted with dinosaurs but were mouse-
  sized and ate insects.
• These early mammals were nocturnal and endothermic.
• Mammals took over all habitats and diversified once the
  dinosaurs went extinct.
• Mammal-endothermic vertebrate that possesses
  mammary glands and hair
           All Mammals have:
• 1. Mammary glands
• 2. Hair
• 3. Lungs
• 4. Muscular diaphragm that separates lungs and
  heart from the rest of the body
• 5. 4 chambered heart
• 6. Reproduce sexually with internal fertilization (a
  few exceptions)
• 7. Most give live birth with few exceptions
                                    Mammals




   Placentals                   Monotremes                       Marsupials




Embryo develops
                                    Lay eggs                    Have a pouch
  In a uterus



                                                 Only live in
                Placenta provides
                                                Australia and                 Young born before
                   Nutrients to
                                                Neighboring                    Fully developed
                     embryo
                                                   islands

                                                                                                 Most live in
                               Contains amnion             Mixture of reptilian                 Australia and
                             like bird and reptile          And mammalian                        Neighboring
                                     eggs                    characteristics                   Islands, except
                                                                                                   opossum

                                                                                                                 Kangaroos
                                                                                Platypus and                       Koalas
                                               4,200 species
                                                                                   echidna                       Opossums
                                                                                                                    Etc..
Monotremes
Marsupials
Marsupial babies
Placental Mammals
             Early Hominids

• Oldest evidence for bipedalism or upright
  walking was Australopithecus about 4 mya.
• Famous fossil called Lucy.

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:6
posted:10/26/2012
language:English
pages:37