Heel hump
The heel hump , also called internal callus or metatarsal tubercle , is a raised outgrowth on the proximal end of the metatarsal bone (tarsus) or on the base of the innermost toe on the sole of the foot of amphibians , especially frogs . The cartilaginous base of the keratinized heel hump is called prehallux. Some authors interpreted this spur as a reduced sixth toe. In some frogs such as the common spadefoot toads (compare: European common spadefoot toads , American common spadefoot toads ) the heel hump is shaped into a sharp-edged, hardened digging shovel. Herpetologists use it as an aid to differentiating between species, such as the water frogs .
In mammals, the protrusion of the calcaneus that supports the heel - the calcaneal tuberosity - is called the heel hump.
Individual evidence
- ^ Rainer Günther: The water frogs of Europe . (= New Brehm Library. 600). Ziemsen-Verlag, Wittenberg Lutherstadt 1990, ISBN 3-7403-0234-8 .