Great appendages are large
claw-like
appendages which attach to the heads of the "great appendage arthropods", a group whose
monophyly is debated, but which includes the
anomalocaridids. The great appendages are used in food manipulation;
Anomalocaris used them to manipulate prey such as
trilobites, while
Laggania used them to
filter algae and similar small particles from the water in which it dwelt. They have been suggested to be homologous with the
antennule of the
euarthropods, or the
chelicerae of chelicerates, although the latter possibility has been discounted.