What are Lizards?
A: Lizards are a widespread group of squamate reptiles, with over 7,000
species.
Lizards range in size from chameleons and geckos a few
centimeters long to what?
A: The 3-meter-long Komodo dragon.
Most lizards are quadrupedal, running with a what?
A: A strong side-to-side motion.
Some lineages (known as “legless lizards”) have
secondarily lost what?
A: Their legs and have long snake-like bodies.
Some such as the forest-dwelling Draco lizards can
what?
A: Glide.
They are often territorial, the males fighting off
other males and signaling, often with bright
colors, to do what?
A: Attract mates and to intimidate rivals.
Lizards are mainly carnivorous, often being what kind
of predators?
A: Sit-and-wait.
Many smaller species eat insects, while the Komodo eats
mammals as big what?
A: Water buffalo.
Lizards make use of a variety of antipredator
adaptations, including what?
A: Venom, camouflage, reflex bleeding, and the ability to sacrifice and
regrow their tails.
Lizards typically have rounded torsos, elevated heads
on short necks, four limbs and long tails, although some are what?
A: Legless.
As in other reptiles, the skin of lizards is covered in
what?
A: Overlapping scales made of keratin.
This provides protection from the environment and
reduces what?
A: Water loss through evaporation.
This adaptation enables lizards to thrive where?
A: In some of the driest deserts on earth.
The skin is tough and leathery and is what?
A: Shed as the animal grows.
The dentitions of lizards reflect their wide range of
diets, including what?
A: Carnivorous, insectivorous, omnivorous, herbivorous, nectivorous, and
molluscivorous.
Species typically have uniform teeth suited to what?
A: Their diet, but several species have variable teeth, such as cutting
teeth in the front of the jaws and crushing teeth in the rear.
The tongue can be extended outside the mouth and is
often what?
A: Long.
In the beaded lizards, whiptails and monitor lizards,
the tongue is what?
A: Forked and used mainly or exclusively to sense the environment.
The tongue is continually flicking out to do what?
A: To sample the environment.
In geckos, the tongue is used to lick what?
A: To lick the eyes clean: they have no eyelids.
Chameleons have very long sticky tongues which can be
extended rapidly to do what?
A: To catch their insect prey.
Three lineages, the geckos, anoles, and chameleons,
have modified the scales under their toes to form what?
A: Adhesive pads, highly prominent in the first two groups.
The pads are composed of what?
A: Millions of tiny setae (hair-like structures) which fit closely to the
substrate to adhere using van der Waals forces.
In addition, the toes of chameleons are divided into
what?
A: Two opposed groups on each foot (zygodactyly), enabling them to perch on
branches as birds do.
Skinks that live largely covered by loose soil rely
heavily on olfaction and touch, while geckos depend largely on what?
A: acute vision for their ability to hunt.
Monitor lizards have acute what?
A: Vision, hearing, and olfactory senses.
Some lizards make unusual use of their sense organs:
chameleons can steer their eyes in different directions, sometimes providing
what?
A: Non-overlapping fields of view, such as forwards and backwards at once.
Lizards lack external ears, having instead a what?
A: A circular opening in which the tympanic membrane (eardrum) can be seen.
Many species rely on hearing for early warning of
predators and flee at what?
A: The slightest sound.
As in snakes and many mammals, all lizards have a
specialized olfactory system, the vomeronasal organ, used to detect what?
A: Pheromones.
Monitor lizards transfer scent from the tip of their
tongue to where?
A: The vomeronasal organ.
