Final answer:
The anatomical characteristics needed for a V-shaped mandible include the ramus and the angle of the mandible, the coronoid and condylar processes, and the attachment sites for muscles such as the masseter. The morphology of mandibles varies widely among animals as an adaptation to their diets and lifestyles.
Step-by-step explanation:
The anatomical features that are necessary for forming a certain structure like a V-shaped mandible include several components and landmarks of the lower jaw. The mandible is the only moveable bone of the skull and starts as paired right and left bones in infants and fuses to form a U-shaped adult mandible in the first year. Critical to the V-shaped mandible are the ramus of the mandible and the angle of the mandible where the body and ramus meet.
Each ramus has two projections - the anterior coronoid process, which attaches to biting muscles, and the posterior condylar process with the condyle, the articulating surface with the temporal bone, forming the temporomandibular joint for mouth movements. The alveolar process that serves to anchor the lower teeth and the muscle attachments like those for the masseter muscles, which function in chewing are other essential landmarks.
Morphological variation in the mandible reflects adaptation to different diets and lifestyles as observed in the animal kingdom from the robust herbivorous grinders to the specialized feeders like insectivorous chameleons or nectar-sipping hummingbirds.