The family Aspidosiphonidae is characterized by an oval disk with short tentacles, arranged in a crescent-shape made of an enclosed nuchal organ. It has a canal of sacs in the coelom, lying in a continuous band. The anal and caudal shield (at the anterior end) are both made up, not of chitin, but of a horny protein. It is of note that most, but not all, of the Aspidosiphonidae family has a caudal shield. The family also has two nephridia.[1][2][4][5]
^ abDitadi, A.S.F. & Migotto, A.E. (1982): O Filo Sipuncula. Concelho Nacional de Desemvolvimento Cientifico e Tecnologico CNPq Brasilia. 43p.
^Cutler, Edward B. & Gibbs, Peter E. (1985): A Phylogenetic analysis of higher taxa in the Phylum Sipuncula. Systematic Zoology 34(2):162-173.
^ abcdefghijklmnopqrstuvwxCutler, Edward B. & Cutler, Norma J (1989): A revision of the genus Aspidosiphon (Sipuncula: Aspidosiphonidaea). Proceedings of Biological Society of Washington 102(4):826-865 Bistor