Biol. Lett. doi: 10.1098/rsbl.2008.0217 (2008)

The mothers of many species give their all to rear their young. But the South American amphibian Siphonops annulatus takes this dedication to an unusual extreme by allowing her offspring to eat her skin.

Alexander Kupfer of the Friedrich-Schiller University in Jena, Germany, and his colleagues report that S. annulatus nestlings have 44 spoon-shaped teeth. These teeth bear claw-like protrusions that the nestlings use to tear away the outer layer of their mother's skin.

The same group has previously described 'maternal dermatophagy', as such skin-feasting is called, in an African amphibian, Boulengerula taitanus. It therefore seems likely that the behaviour arose before Africa and South America separated, more than 100 million years ago.