Download Reptiles and Birds

Ms. Moore
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Body Plan: land vertebrates
◦ Well-developed skull
◦ Backbone and tail
◦ Two limb girdles with four limbs
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A reptile is a vertebrate that has a dry, scaly skin,
lungs, and terrestrial eggs with several
membranes.
Evolved from amphibian-like ancestors;
developed under dry conditions; age of the
dinosaurs (variety)  extinction
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Body Temperature Control
◦ Ectotherms: rely on behavior to control body temp.
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Feeding
◦ Mostly herbivores or carnivores with adaptations to
assist in feeding
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Respiration
◦ Cannot diffuse through skin, use spongy lungs
surrounded by muscles to help expand and collapse
cavity
◦ May have flaps of skin over nostrils to help when
underwater
◦ Most have two lungs, some snakes only have one
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Circulation
◦ Double-loop (1 to lungs, the other to body)
◦ 3 or 4 chamber heart with partial septum dividing the
ventricle (crocodiles)
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Excretion
◦ Urine (ammonia or uric acid) produced in kidneys 
bladder/cloaca
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Response
◦ Similar to amphibian; cerebrum and cerebellum are larger
◦ Reptiles have a pair of nostrils and sensory organs in roof
of mouth = smell
◦ Simple ears with external eardrum and 1 bone
◦ Body heat detectors
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Movement
◦ Wide variety of movements specialized to body
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Reproduction
◦ Internal Fertilization! Penis-like organ delivers
sperm to female cloaca
◦ Embryos are covered with membranes and a
leathery shell
◦ Most are oviparous, some are ovoviviparous
◦ Amniotic egg: embryo can develop without drying
out
 4 membranes:
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Amnion: surrounds and cushions developing embryo
Yolk sac: food supply
Chorion: regulates gas exchange
Allantois: stores waste from embryo
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Lizards and Snakes
◦ Order: Squamata, means “scaly reptiles”
 Lizards: have legs, clawed toes, external ears, and movable
eyelids
 Snakes: lost both pairs of legs during evolution; efficient
predators; some can produce venom
*Draw Figure 31-8: The Amniotic Egg (p803)
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Crocodilians
◦ Order: Crocodilia
 Crocodiles: habitat includes fresh or salt water; native to Africa,
India, SE Asia
 Alligators: habitat includes fresh water; native to N/S Americas
 Caimans: same as alligator, but smaller
 Gavials
◦ Fierce carnivores; guard eggs/young
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Turtles and Tortoises
◦ Order: Testudines
 Turtle: lives in water
 Tortoise: lives on land
 Terrapin: found in water that is somewhat salty
◦ Shell is built into the skeleton:
 Carapace: dorsal part
 Plastron: ventral part
◦ No teeth, horny ridges that cover the upper and lower jaws
◦ Powerful limbs
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Tuataras
◦ Order: last surviving member of Sphenodonta
◦ Found off the coast of New Zealand
◦ Resemble lizards, but lack external ears and retain
primitive scales; have a “third eye” (part of brain)
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Birds are reptile-like animals that maintain
a constant internal body temperature. They
have an outer covering of feathers, two legs
covered with scales, and two front limbs
modified into wings.
◦ Feathers: made mostly of protein and develop
from pits in the bird’s skin
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Evolution
◦ Believed to evolve from extinct reptiles/dinosaurs
◦ Archaeopteryx: early bird or transitional animal of
both dinosaurs and birds?
◦ Did birds and dinosaurs both evolve from an
earlier common ancestor?
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Body Temperature Control
◦ Endotherm: generate own body heat; high metabolism
rate
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Feeding
◦ Beaks are adapted to the bird’s diet
◦ Remember: Crop and Gizzard?
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Respiration
◦ Highly efficient; allows birds to maintain their high
metabolic rate = flight
 Air sacs: direct air through the lungs in a one way flow
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Circulation
◦ 4 chambered hearts; 2 separate circulatory loops
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Excretion
◦ Similar to reptiles, except uric acid crystals can be seen
in a white, pasty form
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Response
◦ Well-developed sense organs; brain that can quickly
interpret and respond to signals
◦ Cerebrum: behaviors like nest building, flying, care of
young, courtship, and mating (very large)
◦ Cerebellum: uses precise, coordinated movements
◦ Medulla Oblongata: heartbeat
◦ Optic Lobe: eyesight; see color very well
◦ Olfactory Bulb: smell; very small
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Movement
◦ Some birds cannot fly:
 Ostrich: walk/run
 Penguin: swim
◦ Bones form a sturdy, but lightweight frame
◦ Large chest muscles power flight
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Reproduction
◦ Both male and female reproductive tracts open to the
cloaca  “cloacal kiss”; some may have penis
◦ Amniotic eggs with hard outer shells; incubated until
hatch
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Over 30 orders of birds
◦ Passerines/Perching Birds: songbirds; over 5000
species
◦ Pelicans and Relatives: aquatic ecosystems
◦ Parrots: colorful and noisy; feet holds food
◦ Herons and Relatives : wading in aquatic
habitats
◦ Cavity-Nesting: live in holes made in trees,
mounds, or underground tunnels
◦ Birds of Prey: raptors; fierce predators with
hooked bills and sharp talons
◦ Ostrich and Relatives: flightless birds