Squamata:
(USC)
- Lizards cannot lift themselves above their limbs
- They crawl along the ground to move
- Some can crawl vertically because they have suction cup like tissue on their feet
- Lizards evolved from legless amphibians that generally hunted for prey in the water
- As food sources became more abundant on land, some lizards grew appendages and solely hunted on land, these are the lizards that are seen today
- Snakes do not have appendages or legs but slither on the ground
- There are four types of snake movement; lateral undulation, sidewinding, concertina, rectilinear, and side-pushing
- Lateral undulation is the most common type of movement in snakes
- Sidewinding is use by snakes to nave themselves on smooth or slippery surfaces
- Concertina is an inchworm-like motion that relies on static friction
- Rectilinear locomotion is just moving in a straight line and is used by larger snakes such as boas
- Side-pushing is like sidewinding but involves a more vigorous action, when a snake wants to get away from a predator
(USC)
Testudines:
(Britannica)
- Sea turtles have large flippers in place of normal appendages
- This allows them to propel themselves through the water
- Terrestrial turtles have short arms and legs, but are considerably slowed by their massive shell
- All turtles were originally amphibious and not until 120 million years ago did they split into terrestrial-based and sea-based turtles
(Britannica)
Crocodilia:
- The whole order of Crocodilia generally have the same type of locomotion
- In water, they propel themselves using their tails
- In shallow water, they also use their webbed feet to swim
- When waiting for prey or just relaxing, they generally keep their head and back exposed above the water
- When sneaking up on prey, they will submerge themselves completely
- On land, they either belly-crawl, walk, or gallop using their legs to propel themselves
- Belly-crawling is like slithering on the ground
- Walking is when they lift themselves off of the ground with their legs, they can move faster in this position than crawling
- Galloping is used for charging prey or escaping predators
(SPH)
Sphenodontia:
(Wikipedia)
- Tuataras are very sedentary and only move when they have to
- But they can move very quickly over short distances if there is danger present
- Their feet are much like that of a lizard
- They have rough, claw-like fingers that help them run
(Wikipedia)