The Spectacled Petrel is a member of the Procellaria genus, and in turn is a member of the Procellariidae family, and the Procellariiformes order. As a member of the Procellariiformes, they share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. Although the nostrils on the Prion are on top of the upper bill. The bills of Procellariiformes are also unique in that they are split into between 7 and 9 horny plates. 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.Finally, 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. In 2004, BirdLife International split the Spectacled Petrel, Procellaria conspicillata, from the White-chinned Petrel, Procellaria aequinoctialis, which had been considered conspecific or even a color morph.