Chapter 32: Reptiles and Birds
Section 1: Reptiles
What Is A Reptile?

Reptiles are vertebrate animals that have lungs, a scaly skin, and a special type of
egg – adaptations that enable them to live their entire life out of water

Reptiles are widely distributed over much of the Earth

The reptiles ________________________________ helps prevent loss of body water

The tough, scaly layer of skin does not grow when the rest of the reptile grows, so it must
be ____________________________________________________ when a reptile
increases in size

Reptilian eggs are surrounded by a shell and several membranes that create a protected
environment in which the embryo can develop
o _____________________________________

Amniotic eggs also contain a __________________

The yolk is rich in nutrients that the developing embryo uses until it is ready to hatch

Reptiles have an efficient ___________________________________________

To exchange gases with the environment, reptiles have at least one efficient
________________
Evolution of Reptiles

Because several fossils show characteristics of both amphibians and reptiles, it is difficult
to say exactly when the first true reptiles appeared on Earth

One determining factor that separates living reptiles from amphibians is the
________________________________________ they produce

Because we cannot tell what kind of eggs these fossil animals laid, they must remain on
the amphibian-reptilian borderline

These animals are often called ________________________________________

Throughout most of the Carboniferous Period, amphibians greatly outnumbered reptiles

But during the Permian Period, the Earth’s surface and climate changed dramatically

The climate became cooler and less humid

Many of the great swamps dried up

These changes made life difficult for a large number of water-dependent amphibians

But such was not the case with the reptiles

It was during this time that they began their great period of _________________________
____________________________

One early reptile line developed into a fascinating group pf mammal like reptiles that
displayed a mix of reptilian and mammalian characteristics

Although these animals were extremely successful at first, they became extinct in just a
few million years

Toward the end of the Triassic Period, about 195 million years ago, the mammal like
reptiles were suddenly replaced in the fossil record by another group of reptiles that had
remained in the background for millions of years – the _____________________________

During the late Triassic and Jurassic Periods, a great adaptive radiation of the dinosaurs,
or “_________________________________________,” took place

The Triassic Period also saw the appearance of crocodiles and alligators, as well as the
first birds

At the end of the Cretaceous Period, about 65 million years ago, something happened to
cause a worldwide ____________________________________________

Within a few million years, dinosaurs and most other animal and plant groups became
extinct

Whatever happened at the end of the Cretaceous Period resulted in the death of virtually
all the great and terrible lizards

The disappearance of the dinosaurs left open many niches for animals, both on
__________________ and in the ____________________
Form and Function in Reptiles

Reptiles exhibit numerous variations in structure and behavior

Some – for example, turtle, crocodiles, and lizards – move about on __________________

Others move about _________________________________
o Snakes and certain lizards
Feeding

Some are herbivores and others are carnivores

Some have ________________________________ to capture prey

Others kill their prey by ____________________________ it first

Some reptiles have _______________________________________ that can catch
insects
Respiration

May reptiles are able to expand their chest cavity to inhale and collapse the cavity to force
air out

Although most reptiles have two lungs, some species of snakes have only one

You know that it is impossible for a person to breathe and swallow
________________________________________

Snakes have a _____________________________________ in the floor of their mouth
through which they breathe, so they don’t suffocate in the time it takes them to swallow
their prey

This tube can be extended out of a snake’s mouth while it is dining
Internal Transport

Reptiles have a well-developed ___________________________________ circulatory
system

One of the two loops brings blood to and from the lungs and the other loop brings blood to
and from the rest of the body

Have a well-developed ________________________

Have a well-developed circulatory system
Excretion

Eliminate wastes in the form of _____________________, which is produced in the
__________________________

Urine flows through tubes directly into a ______________________ similar to that of
amphibians

In some reptiles, a __________________________________________ stores urine
before it is expelled
Response

Most reptilian sense organs are well-developed

Have complex eyes that contain _____________________________________________

Many snakes have a good sense of _______________________

Some reptiles have simple ears to hear (eardrum, tympanic membrane)

Some reptiles are able to gather heat information from their environment
Movement

The reptilian muscle and skeletal systems exhibit many advances over those of
amphibians

Reptiles with legs have larger, stronger limbs whose movements are
___________________________________________

Snakes, which lost their legs in the course of evolution, move by pressing large ventral
________________________ against the ground
Reproduction

Reptiles lay eggs that hatch into animals that resemble ____________________________

Virtually all reptiles reproduce through _________________________________________,
which means that a male deposits sperm into the body of the female

From the outside, it is extremely difficult to tell the _________________ of a reptile

Most reptiles provide ______________________________ care for their young
Tuataras

The tuatara is the only surviving member of the order _____________________________

Resembles reptiles that lived during the ____________________________________

Tuataras are found only on a few small islands off the coast of
__________________________________

They are active at ____________________

They have a pineal gland that contains cells that are sensitive to light

They use it to detect changes in day length
Lizards and Snakes

Order __________________________

Most lizards have _______________, clawed _______________, external ____________,
and moveable __________________________

Some have evolved into highly specialized forms

The __________________________ are the only reptiles alive today that provide some
idea of what small dinosaurs may have been like
o Quite intelligent and active
o Eat birds and mammals
o Largest are the _______________________________________

Snakes are lizards that have lost both ________________________________ during their
evolution

Although being legless may seem to be a disadvantage, snakes are efficient and effective
predators in the niches they occupy

The distribution of snakes on Earth is limited only by ______________________________

Snakes vary in __________________

The ability of certain types of snakes to produce _________________________________
has caused people to fear snakes
o More people in the US die from ______________________________ than snake
bites
Crocodilians

Order ______________________________

Alligators, crocodiles, caimans, and gavials

Crocodilians are among the largest living reptiles
o Can grow up to __________________ in length

Live only in the tropics and subtropics, where the climate is ________________________
________________

Alligators and caimans live only in ___________________________ and are found in the
_________________________________________________

Crocodiles may live in either _______________________________________ and are
native to _________________________________________________________________
Turtles

Order _________________________________

Turtles live in _____________________

Tortoises live on _________________

All have some sort of ________________________ covering their body

The shell consists of two parts: a dorsal part, or __________________________, and a
ventral part, or ____________________________

The animal’s backbone is ________________________ to the inside of the carapace, and
its head, legs, and tail stick out through holes where carapace and plastron join

Tortoises usually have a high, domed carapace and stubby, elephant-like legs

Tortoises pull into their shells to protect their more delicate body parts

In some species, the front end of the plastron is hinged and folds up to further seal out
predators

Turtles are adapted to ______________________________________________________
________________________

The legs and feet of many aquatic turtles have developed into ______________________

Certain aquatic species cannot pull back into their shell completely, but they do have
powerful _______________ that are capable of biting if attacked
How Reptiles Fit into the World

Reptiles are important ______________________________ in many ecosystems

_____________________________________ are now in danger of extinction
o Turtle soup and turtle eggs
o Used to manufacture ________________________
o Destruction of _______________________________________