Snakes movement

Question 1

What animals have snakes evolved from ?

Answer 1

Burrowing lizards who had reduced or lost limbs.

Question 2

How many vertebrae to snakes have and what number of muscles are attached?

Answer 2

100-400 trunk vertabrae. There are 12 or more bundles of muscles attached to each vertebrae.

Question 3

What is lateral undulation and what are it’s features ?

Answer 3

This is the classic serpentine movement. Body parts move sideways to push body forward. At least 3 points in contact with the ground. Lateral movements cancel out leaving forward forces to push the snake forward.

Question 4

What s the name for ventral scales ?

Answer 4

Scutes.

Question 5

How does rectilinear progression occur ?

Answer 5

Series of contracting, fixed and stretching scutes. Causes the snake to move forward.

Question 6

What is advantageous about rectilinea progression ?

Answer 6

When stalking prey only the head can be seen.

Question 7

What is side winding ?

Answer 7

The fastest method of movement, used most profficiently by sand snakes

Question 8

What genus uses parachuting flight and how ?

Answer 8

Chrysoplea. Ventral scales are hinged and create concave creating extra drag when dropping from heights.

Question 9

What two adaptations do swimming snakes have ?

Answer 9

• Wide, flattened bodies

- Dorsal nostrils