In detail, describe an invertebrate anatomical structure, organ or organ system (or related group of structures) in a single species (or group of related species). Your paper must discuss the function of the structure(s) and the importance of the structure to the evolution of the species (or group of species) and its significance to the survival of the individual animal. Your paper must address the evolution of the structure as it is known or hypothesized to have evolved. The paper may NOT be on a vertebrate animal. This is NOT a general summary review of an invertebrate animal
LENGTH: A minimum of 2500 words NOT INCLUDING ANY OF THE FOLLOWING:
REFERENCES: A minimum of at least SIX DIFFERENT references (see reference specifics below). You may use more than six references and the expectation is that you will have more than six different sources.