Temporalis Muscle

Some articles on muscles, temporalis:

Machairodontinae - Osteology - Cranial Osteology
... for mammals are the two pairs of large muscles along the back of the jaw the temporalis and masseter muscles ... These muscles of the head have the capacity to be powerful and undergo a great degree of modification for ranging bite forces, but not very elastic due to their thickness, placement, and strength ... To open the mouth wider, these species needed to change the formation of these muscles, namely to make them smaller and change their shape ...