Question

The size of the quadruped atlas is much larger than that of the biped. It is designed this way because?

1) Gravity acts on the quadruped differently
2) Muscle attachments require larger boney protrusions
3) It would look funny if animals had smaller necks

Answer 1

The quadruped atlas is larger than that of a biped to accommodate muscle attachments require larger boney protrusions. The correct answer is an option 2

Step-by-step explanation:

The size of the quadruped atlas is much larger than that of the biped primarily because muscle attachments require larger bony protrusions. The effect of gravity on land-dwelling quadrupeds led to necessary changes in their skeletal structure to support their body weight. The vertebrae, particularly in the neck region, evolved to allow the head movement to be independent of the body, which was facilitated by a firmer, more ossified vertebral column that provided the necessary strength and reduced torsional strain. Additionally, in quadrupeds, the appendicular skeleton had to evolve, with limbs moving from a splayed position to being placed underneath the body, thus allowing a more efficient stride that required less force to move forward.

With the change in limb positioning and the strengthening of the vertebral column, these anatomical adjustments lead to a decrease in the size of specific muscles and an increased range of motion in others. These changes were part of a complex set of skeletal adaptations that allowed terrestrial animals to move efficiently on land, contrasting with their aquatic ancestors. So, The correct answer is an option 2

Answer 2

The size of the quadruped atlas is larger than that of the biped due to the Gravity acts on the quadruped differently (Option 1).

Step-by-step explanation:

The size of the quadruped atlas is larger than that of the biped because of the effect of gravity and the need for increased strength and support. The lack of buoyancy on land means that the body weight is suspended on the limbs, leading to increased strengthening and ossification of the limbs.

Additionally, changes to the axial skeleton, including a more ossified vertebral column, allow for better support and reduce strain while supporting the body's weight. The design of the quadruped atlas also reduces the jarring to the head caused by the impact of the limbs on the ground.

Thus, the correct option is number 1.