Which of the following adaptations is NOT typically found in leaping quadrupeds?

The adaptation that is not typically found in leaping quadrupeds is a shorter lumbar region. Leaping quadrupeds, such as certain species of monkeys or other mammals that utilize leaping as a form of locomotion, generally have a more elongated lumbar region. This extended lumbar region provides greater flexibility and range of motion in the spine, allowing for more effective and powerful leaps.

In contrast, having a longer lumbar region facilitates the necessary movement and flexibility required for leaping, as it allows the animal to bend and extend its body more efficiently during the takeoff and landing phases of jumping. This is critical for maintaining balance and control while in the air.

The other adaptations listed—longer limbs than arms, extended hind limbs, and strong leg muscles—are all characteristic of leaping quadrupeds. Longer limbs help achieve greater distances with each leap, extended hind limbs contribute to propelling the body upward and forward, and strong leg muscles are essential for the power needed to initiate leaps. These physical features are adaptations that enhance the overall leaping ability of these animals.