Project Summary A global collection of the deep-sea Aplacophora comprising some 20,000 specimens from about 60 surveys and expeditions will be monographed and a relational database developed along with keys, images, and short descriptions will be made available on the Internet. The Aplacophora are one of the seven extant classes of the Phylum Mollusca .
Aplacophorans are vermiform and spicule-bearing.
There are about 300 described species. The aplacophorans are mollusks of broad phylogenetic interest. Within the Class Aplacophora itself lie tests of the hypothesis that they are progenetic. Cladistic analyses of both morphology and DNA are being used to clarify phylogenetic relationships among the Aplacophora and to understanding the evolution of structures both within the Class and within the Phylum. The aplacophorans are an important part of the deep-sea benthos.