Which of the following is NOT a characteristic of strepsirrhines?

Strepsirrhines, which include lemurs, lorises, and galagos, possess several distinct anatomical and physiological traits that differentiate them from other primates. One of their key characteristics is the presence of a moist rhinarium, which is a feature that enhances their sense of smell. They also typically have a post-orbital bar, which is a bony structure that helps support the eye orbits.

The correct answer, pertaining to the fused mandibular symphysis, is not a trait of strepsirrhines. In contrast, the majority of strepsirrhines retain a more primitive characteristic of having a unfused mandibular symphysis, which allows for greater flexibility in their jaw structure, facilitating the processing of their food.

Understanding that strepsirrhines generally exhibit a range of less derived features aids in highlighting why the fused mandibular symphysis is inconsistent with their anatomical profile. The presence of a tapetum lucidum, a reflective layer in the eyes that improves night vision, is another feature associated with many strepsirrhines, particularly those that are nocturnal.