Final answer:
The body plan of a snake is distinct from typical reptiles due to the lack of eyelids, limbs, and external ears, alongside specialized jaw adaptations that facilitate swallowing large prey whole. Snakes also have movable quadrate bones for wide mouth opening.
Step-by-step explanation:
In what way is the body plan of a snake different from that of a typical reptile? Snakes have a unique body plan among reptiles with several distinctive features. Unlike most other reptiles, snakes lack eyelids, limbs, external ears, or forelimbs. Additionally, their skulls have unique adaptations; snakes possess highly movable quadrate bones that allow them to open their mouths wide enough to swallow large prey. This capability is in part due to the eight rotational joints in their skull and the lack of bony or ligamentous attachment in their mandibles, which is replaced by skin and muscle connections for dynamic gape expansion.
While lizards, for example, often have four legs, most snakes have evolved to become completely legless, with the exception of boids that retain vestigial hindlimbs. The morphological adaptations of snakes, from their jaw structure to their lack of limbs, are related to their specialized feeding habits, as they predominantly consume animals, birds, eggs, fish, and insects, either by swallowing them whole, using constriction, or by envenomation.