SPINY ANTEATER (MONOTREME)
Unlike other most anteaters, spiny anteaters (or echidnas), genus Tachyglossus, are also members of the subclass Holotheria. Like all monotremes, they are found only in Australia and New Guinea.

Unlike duck-billed platypus females, which produce eggs only from the left ovary, spiny anteater females have two functional ovaries. A female anteater lays a single egg that is kept in her pouch for seven to ten days until the youngster hatches. After six to eight weeks, the offspring leaves the pouch as its spines begin to harden and cover its entire body.

As a defensive behavior, spiny anteaters are known to curl up into a spine-covered ball. They also dig well and can wedge themselves into a burrow, using their spines as an anchor that causes them to be difficult to remove.

In addition, spiny anteaters have spurs on their ankles that probably serve in fighting and defense, although the spurs are not poisonous.