This mollymawk was once considered to be the same species as the Salvin's Albatross, Thalassarche salvini and the Chatham Albatross, Thalassarche eremita, but they were split around 2004. In 1998, Robertson and Nunn, suggested a four-way split including the White-capped Albatross, Thalassarche steadi. The three-way split was accepted by Brooke in 2004, the ACAP in 2006, SACC in 2008, and BirdLife International by 2000. James Clements seems to be the last major holdout on the three-way split. The fourth split, steadi, was only accepted by the ACAP in 2006, and BirdLife International in 2008. Finally, following Brooke, this species was shifted from Diomedea to Thalassarche, which was generally agreed upon by most experts.
Mollymawks are a type of Albatross that belong to Diomedeidae family and come from the Procellariiformes order, along with Shearwaters, Fulmars, Storm-petrels, and Diving-petrels. They share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. Although the nostrils on the Albatross are on the sides of the bill. The bills of Procellariiformes are also unique in that they are split into between 7 and 9 horny plates. Finally, they produce a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus. This is used against predators as well as an energy rich food source for chicks and for the adults during their long flights. They also have a salt gland that is situated above the nasal passage and helps desalinate their bodies, due to the high amount of ocean water that they imbibe. It excretes a high saline solution from their nose.
