Reptiles are a class of vertebrates made up mostly of snakes, turtles, lizards, and crocodilians. These animals are most easily recognized by their dry, scaly skin. Almost all reptiles are cold-blooded, and most lay eggs—though some, like the boa constrictor, give birth to live young.

1. Class Reptilia
PREPARED BY:
SKY O. LAWA-AN
BSBIO-1

2. WHAT ARE REPTILES?
Reptile is a member of class Reptilia. It is a group of air-
breathing vertebrates that has internal fertilization and
epidermal scale covering part of their body. The major group of
living reptiles are turtles, Tuatara, Squamata, and a crocodilian.
Reptiles is a word derived from Latin, in which reptiles meaning
is “one who creeps”. The study of traditional reptile orders is
known as herpetology.

3. DEFINITION
• Reptiles are defined as a vertebrate animal of a class that
includes snake, lizards, turtles and tortoise. And they are
distinguished by having dry scaly skin and typically laying soft-
shelled eggs on land. Some of the examples of reptiles are
lizards, Turtles, Snakes, Chameleons, Dinosaurs, Crocodiles,
Scaled reptiles, Geckos, Skink, Sauria, Diapsid, Plesiosauria
and also there are many other examples of reptiles.

4. CHARACTERISTICS
Following are the important
characteristics of the
animals belonging to Class
Reptilia:
• These are creeping and
burrowing terrestrial animals
with scales on their body.
They are cold-blooded
animals found in most of the
warmer regions of the world.
Their skin is dry, and rough,
without any glands.
EXAMPLE
• With few exceptions, modern
reptiles feed on some form
of animal life (such
as insects, mollusks, birds, fr
ogs, mammals, fishes, or even
other reptiles).

5. HABITAT
• Reptiles rely on conditions
that allow them to maintain
their body temperature - they
need to be able to bask and
avoid extremes of
temperature.
• Access to direct sunlight.
• Shelter from the elements,
such as wind and excessive
heat.
EXAMPLE
• Aquatic habitats
• Dry habitat

6. REPRODUCTION
• They reproduce by laying eggs
which hatch into babies.
• This process is
called oviparity.
• Female reptiles lay their
fertilized eggs in nests they
dig or on the ground under
leaves or other debris for
camouflage and protection.
EXAMPLE
• Some reptiles lay eggs and
others deliver live young.
• Females do not need the
presence of a male in order to
lay eggs.
• There are subtle differences
between males and females in
most species of reptile, but in
others, the differences are
obvious.
• Most reptile eggs are artificially

7. GENERAL BEHAVIOR
• Spitting venom
• Balling (coiling up and hiding
the head under the body)
• Secreting foul-smelling odors
from the musk gland
• Flicking a tail (some lizards
have thick or horny tails that
are a useful weapon)
EXAMPLE
• The most common defense for
reptiles is to avoid enemies.
• If they feel threatened, snakes
and lizards tend to move away.
• Crocodiles and turtles will tend to
sink down into water if
threatened.

8. Turtles
• Order of reptiles known as Testudines,
characterized by a special shell
developed mainly from their ribs.
• Modern turtles are divided into two
major groups, the Pleurodira (side-
necked turtles) and Cryptodira (hidden-
necked turtles), which differ in the way
the head retracts.
• They are found on most continents,
some islands, and in the case of sea
turtles, much of the ocean.
• Like other amniotes (reptiles, birds,
and mammals they breathe air and do
not lay eggs underwater, although many
species live in or around water.

9. Class: Reptilia (Reptiles)
External observation: “Red-Eared Slider”
Internal anatomy: “Red-Eared Slider – Anatomy”

10. Squamata
• This type of reptile mainly consists of
lizards and snakes.
• It is one of the largest order of
reptiles also known as scaled reptiles.
• It is one of the most varied order of
reptiles in size ranging from 16 mm
(dwarf gecko) to 5.1m (green
anaconda) and now a new extinct
species called mosasaurs, which
reached a length of 14m.

11. Class: Reptilia (Reptiles)
External observation:
“Cobra”
Internal anatomy:
“Cobra– Anatomy”

12. Crocodilian
• In this type of reptile, mainly discuss
crocodiles and alligators.
• It is mostly large, predatory, and semi-
aquatic animals.
• The body of a crocodilian is large,
solidly built, lizard-like reptiles and
they have long flattened snouts.
• They have a laterally compressed tail,
and eyes, ears, and nostrils at the top
of the head.
• They can swim well in the water and
also they can walk (high walk and the
low walk) on the land.

13. Tuatara
• In this type, we discuss lizard-like
species.
• The name ‘tuatara’ is derived from
Maori language and that means peak
on the back.
• It has only one species, that is
“Sphenodon punctatus” and it is the
only surviving member of its order.
• It is greenish-brown and grey in colour
and its length is 80 cm from head to
tail and weighs around 1.3 kg along
with the spines on the back.

14. Interesting Fun Facts about Reptiles
• Reptiles are one the longest-lived species on the planet, for
example, Aldabra tortoise can live for over 150 years!
• Reptiles first appeared 350 million years ago in fossil records.
• Reptiles' skin is always cool and dry because they do not have sweat
glands, thus they do not produce slime.
• The scales of the snakes are made from the same material, from
which our hairs and nails are made, that is keratin.

15. REFERENCE
Reptile. (n.d.). VEDANTU. https://www.vedantu.com/animal/reptile