Species from this genus are known to parasitise sharks, rays, sawfishes, teleosts and crocodilians.

[2] However, in 2020, František Moravec and Jean-Lou Justine considered this taxon to be invalid on the ground that "its type species [i. e., T. antarctica] has been designated a species inquirenda", and split many of its species into two new-described genera, Euterranova and Neoterranova.

[3] The type specimen and so far only found adult individual available for feature classification of T. antarctica is a female, and many features for such parasites are better discernible among males.

Thus, in an article from 1990, the place of T. antarctica was considered as doubtful.

[3] However, their reclassification was based entirely on analysis of morphological features, and they recognised that molecular analysis again may lead to a changed taxonomy.