Transcript Class Amphibia and Class Reptilia

Class Amphibia, Class Reptilia,
and Class Aves
17C AND 17D
PAGES 520-541
Class Amphibia
 Amphibian means “double life” – a water life and a
land life
 They hibernate (sleep deeply for a long time) in cold
weather
 Three Orders:



Order Apoda – look like worms and live underground
caecilians
Order Caudata – small body with 4 limbs (legs) – salamanders
Order Anura – large head, no tail, short front legs with big
back legs - frogs
Metamorphosis of Amphibians
 All amphibians lay eggs in the water.
 They live in the water until they are teenagers
(tadpoles)
 As adults, they live on the land (frogs)
 Their skin is smooth and soft
 Amphibians have both gills and lungs – the gills will
disappear when they become adults – they use the
gills in the water before they become adults
Circulatory System of Amphibians
 Amphibians have 3 parts to their hearts – called
“chambers”
 There is an extra loop the blood goes through before
going to the body, the same as a human (not like a
fish)
 The blood goes: heart – lungs – heart – body
Class Reptilia
Class Reptilia
 Snakes, lizards, turtles, alligators, crocodiles
 They have thick skin with scales
 Most live on the land, but near water or in wet areas
(mud)
 Most lay eggs that hatch later (oviparous)
 Many hibernate (sleep deeply for a long time) in the
cold
 Use lungs with alveoli (inside of the lung that works
better than a frog) to breathe
Class Reptilia
 Reptilia have stronger hearts with 4 chambers
instead of 3 (like the amphibians)
 Snakes and some lizards have Jacobson’s organs
– part of the top of the mouth that smells the air and
lets the snake know what is nearby
Orders of Class Reptilia
 Order Squamata
 Disarticulating lower jaw (it comes apart to eat bigger things)
 Some venomous species (can have poison)
 Snakes and lizards
 Some snakes have fangs (big teeth)
Orders of Class Reptilia
 Order Testudinata
 Have a protective shell


Carapace (back) and plastron (front)
Turtles and tortoises
 Order Crocodilia
 Alligators and crocodiles
 Order Rhychocephalia
 Spines (like needles) on the backs of the head
 Tuatara (lives in New Zealand only
Class Aves
Class Aves
 All birds, including penguins and ostriches
 They have hollow bones – there is nothing inside the
bones, like a straw
 They have feathers and beaks (mouths)
 They have different kinds of feet


Webbed – used for swimming, like a duck or a penguin
Talons – claws, like an eagle
Kinds of Feathers
 Birds have 2 main kinds of feathers
 1.) Down Feathers – they are soft and keep the bird warm
 2.) Contour feathers – cover most of the bird and give the bird
shape and color

Flight feathers let the bird fly – they cover the bird from the wings
to the tail and are very strong
Digestion in Birds
 Birds have a crop – a place where the food waits
inside the bird to be digested (turned into energy)
 Birds have a proventriculus – a place where
chemicals in the bird are put onto the food to break
the food down
 Birds have a gizzard – after a bird eats stones and
sand, the wet food from the proventriculus is
smashed against the stones and to break the food
down
Other Bird Parts
 Birds cannot get enough oxygen from their lungs, so
they have air sacs – an extra place for air to go into
the bird and for oxygen to get to the bird’s blood
 Birds also have a syrinx – this is in their throats and
lets them sing
Bird Reproduction
 Male birds are usually bigger and more beautiful
than female birds
 Internal fertilization (sperm and egg meet inside the
body)
 Oviparous – the female lays an egg and waits for it to
hatch
 Male birds will court the females (make the girls
interested) by singing or looking beautiful, then
impressing the female by making a nest (bird home)
Bird Reproduction
Bird Behavior
 Some birds migrate – they fly to a place that is
warmer as the weather grows colder
 They usually fly south in the fall (September/October)
and north in the spring (April/May)
 Most birds migrate to the same place all their lives