Lizards make up 60% of reptiles and occur on all continents except Antarctica. They are typically identified by their elongated body and four limbs with a long tail. Lizards vary tremendously in size, from the smallest gecko at 1.5 inches to the largest Komodo dragon at 10 feet. Lizards tails serve different purposes depending on the species, such as providing extra grip for chameleons or breaking off as a defense mechanism to escape predators for other species. Monitor lizards are considered the most advanced lizards as the direct ancestors of snakes, shown through traits like their long, serpentine body and forked tongue.

1. Lizards
By Mr. “3 note days left” Chapman

2. Lizards make up the largest group of reptiles (60% of reptiles).
They occur on all continents except Antarctica.

3. Lizards typically are identified by their elongated body with four
limbs, and a long tail.

4. Lizards typically are identified by their elongated body with four
limbs, and a long tail.
Two-legged lizard

5. Lizards typically are identified by their elongated body with four
limbs, and a long tail.
Two-legged lizard Legless lizard

6. Lizards vary tremendously in size.
Left – smallest lizard
A 1 ½ inch gecko from Hispaniola

7. Lizards vary tremendously in size.
Left – smallest lizard Right – largest lizard – 10 feet
A 1 ½ inch gecko from Hispaniola Komodo Dragon from Indonesia

8. Lizards tails serve several purposes
depending on the species.

9. Lizards tails serve several purposes
depending on the species.
Chameleons have a prehensile tail (grips
like an extra hand).

10. Many lizards have fracture plates in their tail.
If a predator grabs the tail, it will break off
and a new one will regenerate.

11. Many lizards have fracture plates in their tail.
If a predator grabs the tail, it will break off
and a new one will regenerate.
*Some species are even able to autotomize
(autotomy) their tail. They can snap it off
and it wiggles on the ground keeping the
attention of the predator while the lizard
escapes.

12. Many lizards have fracture plates in their tail.
If a predator grabs the tail, it will break off
and a new one will regenerate.
*Some species are even able to autotomize
their tail. They can snap it off and it
wiggles on the ground keeping the
attention of the predator while the lizard
escapes.
Certain species even have brightly colored
tails to make sure it keeps the predator’s
attention.

13. Lizard diets are diverse……
Top left: Most are insectivores

14. Lizard diets are diverse……
Top left: Most are insectivores
Top center: Many, like iguanas are herbivores

15. Lizard diets are diverse……
Top left: Most are insectivores
Top center: Many, like iguanas are herbivores
Top right: some geckos are nectarivores & they pollinate
plants.

16. Lizard diets are diverse……
Top left: Most are insectivores
Top center: Many, like iguanas are herbivores
Top right: some geckos are nectarivores & they pollinate
plants.
Left: Komodo Dragons are predators that can kill large
mammals. They’re the top predators on their islands.

17. Monitor lizards are the most
advanced lizards. They are
the direct ancestors of
snakes. Evidence….

18. Monitor lizards are the most
advanced lizards. They are
the direct ancestors of
snakes. Evidence….
• Long, serpentine body
plan

19. Monitor lizards are the most
advanced lizards. They are
the direct ancestors of
snakes. Evidence….
• Long, serpentine body
plan
• Forked tongue

20. Monitor lizards are the most
advanced lizards. They are
the direct ancestors of
snakes. Evidence….
• Long, serpentine body
plan
• Forked tongue
• Serpentine locomotion

21. Lizards are mostly oviparous. A
few are viviparous.

22. Lizards are mostly oviparous. A
few are viviparous.
Among lizards there are species
that are parthenogenic. The
whole species is female.

23. Lizards are mostly oviparous. A
few are viviparous.
Among lizards there are species
that are parthenogenic. The
whole species is female.
They lay diploid eggs that don’t
have to be fertilized.

24. Lizards are mostly oviparous. A
few are viviparous.
Among lizards there are species
that are parthenogenic. The
whole species is female.
They lay diploid eggs that don’t
have to be fertilized.
Since all the DNA comes from
mom, they’re clones of her.

25. Venomous Lizards
Until recently, it was thought that only two lizard species were venomous.
Those were the Gila Monster & the Mexican Beaded Lizard.

26. Their saliva contains very potent
neurotoxins but they don’t have
fangs.
Instead they have sharp teeth that
create wounds.
The venom simply runs into the
wounds.
To make wounds deep enough for
the salva to leak into, these lizards
must chew their victim.

27. Komodo Dragons were once
thought to have toxins in their
saliva as a result of some of the
bacteria that live in their mouth.
A bite would slowly kill the prey.
However, more recently
scientists have discovered that
the dragons produce the toxins
and several other monitors do
as well.

28. Some of the proteins found in Gila Monster venom are showing
promise as a treatment for Type II diabetes and certain cancers.
Komodo Dragons bite each other when they fight but the bites never
get infected despite the presence of over 50 species of bacteria in their
saliva.
Some of the proteins in their saliva are proving to be valuable as
sources of antibiotics.