This family of two Recent genera , each containing a single species, is found in Australia, Tasmania, and New Guinea.
Echidnas have a body covering of fur intermixed with dorsal and lateral barbless spines.
The average size of males is larger than that of females. The body is robust and muscular, yet supple. The limbs have broad, powerful feet modified for digging, each foot bearing from three to five strong, curved claws. The second toe on the hind foot is elongated and is used for scratching and cleaning the fur and skin. The eyes are smaller than those of the Ornithorhynchidae.