At the time, Compagno chose to maintain Pseudotriakis as the sole member of the family Pseudotriakidae because of its numerous unique traits. More recently, he and other taxonomists have increasingly tended to group Gollum and Pseudotriakis together in the family Pseudotriakidae.
In the past, Compagno chose to classify Pseudotriakis as the sole member of the Pseudotriakidae family due to its unique features. However, more recently, he and other taxonomists have begun grouping Gollum and Pseudotriakis together under the same family name.