Species of the genus Tasmanoplana are characterized by having an elongate, subcylindrical body that is flat ventrally.

The creeping sole occupies more than two thirds of the body width.

The eyes are small and arranged along the body margins in a single row from the anterior to the posterior end.

The parenchymal musculature includes very strong and compact longitudinal fibers forming a ring around the intestine.

[1] The word Tasmanoplana is a combination of Tasmania, the island from which Charles Darwin collected the first specimen of the genus, and Latin plana, flat.