Breaking force Spekia

One molluscan autapomorphy is the radula, the organ used for feeding. Here, for the first time, the performance and failure of taenioglossan radular teeth were tested in a biomechanical experiment which in turn allowed building hypotheses about tooth functionalities. Shear load was applied to tooth cusps with a force transducer until structural failure occurred, the broken area was measured, and finally breaking stress was calculated. These experiments were carried out under dry and wet conditions. Our results show that certain tooth types can resist higher stresses and are rather specialised to loosen food items from a surface, whereas other teeth can only gather food particles. The experiments additionally illustrate the high influence of the water content on the resulting breaking stress. When wet teeth were tested, their ductility and ability to avoid being fractured by an obstacle increased. Their flexibility also allowed them support from teeth of adjacent tooth rows, which made t...