Class Enteropneusta

 Class Enteropneusta
Family Harrimaniidae
Genus Saccoglossus
Saccoglossus bromophenolosus
Saccoglossus pusillus
Saccoglossus kowalevskii
Saccoglossus cambriensis
Genus Harrimania
Harrimania planktophilus
Family Ptychoderidae
Genus Balanoglossus
Balanoglossus carnosus
Genus Ptychodera
Ptychodera flava
Genus Glossobalanus
Glossobalanus minutus


 Commonly called Acorn worms, the enteropneusts are solitary and reproduce sexually. The enteropneust body is divided into three parts: proboscis (protosome), collar (mesosome) and trunk (metasome). Adults display chordate characteristics: pharyngeal gill pores, partially neurulated dorsal cord and a stomochord (similar to chordate notochord.) However, as with all hemichordates, they lack a dorsal postanal tail and segmentation of the muscular and nervous systems.

Cameron, C.B., Garey, J.R. and Swalla, B. J. (2000) "Evolution of the chordate body plan: New insights from phylogenetic analyses of deuterostome phyla." Proc. Natl. Acad. Sci. 97: 4469-4474. (Online)

 Gene Links: Enteropneusta in GenBank