Question

Simian gap is
A) Distance between two nostrils
B) Bony thickening on the front of the ape mandible
C) Distance between two eyebrows
D) None of the above

Answer 1

Hint: Simian shelf is a characteristic feature of the ape mandible. It has a role in reinforcing the jaw and also reducing the movement of the tongue.

Complete Answer:
Simian gap or Simian shelf represents the bony thickening on the front of the ape mandible.
Option A: The wall that separates the two nostrils is referred to as nasal septum.therefore, this is the incorrect option.
Option B: The bony thickening present on the front of the ape mandible is known as the Simian Gap. therefore, this is the correct option.
The key function of this structure is reinforcing the jaw by reducing the tongue movement thereby restricting the muscle areas. In humans, the dental arch represents a collective appearance for the smoothly rounded parabola along with small incisors. This Simian gap amongst the apes is present between their canine and incisors on either jaw end.
Option C: The distance between the two eyebrows is referred to as glabella. Therefore, this is the incorrect option.
Option D: As one of the options is correct, therefore, this is the incorrect option.

Thus, the correct answer to the given question is Option B i.e. bony thickening on the front of the ape mandible.

Note: Simian shelf was evidently visible in the fossil remnants of the early humans.