Papillae are examples of a muscular hydrostat
, biological structures that consist of muscle with no skeletal support (such as the human tongue).
A comparative biomechanical analysis of unarmed schizorhynchs, armed karkinorhynchs, and armed diascorhynchs may provide insight into not only the evolution of these animals, but also the evolution of an increasingly complex muscle articulation from a simple muscular hydrostat
And he notes that the muscular hydrostat idea has already reshaped physiologists' thinking about how the human heart expands after contraction.
Guided in part by nature's muscular hydrostat examples, Wilson expects that such complaint robot arms will be more robust and will be able to operate in tighter, more awkward work spaces than their conventional, rigidlimbed counterparts.
But these bat tongues are extremely rapid because the vascular system that erects the hair-like papillae is embedded within a muscular hydrostat
, which is a fancy term for muscular, constant-volume structures like tongues, elephant trunks and squid tentacles.