Pholidosaurus decipiens was erected for a partial cranium, NHMUK 28432, that was originally assigned to the new genus and species
Petrosuchus laevidens by
Richard Owen in 1878.
Petrosuchus laevidens was based on this cranium and a mandibular ramus called BMNH 41099, both of which were collected from
Swanage, England. A later study in 1911 concluded that the material belonged to two different species; NHMUK 28432 was reassigned to
Pholidosaurus and NHMUK 41099 was designated the lectotype of
Petrosuchus laevidens. The species name
decipiens was coined in reference to Owen's oversight, and
Petrosuchus is now considered a junior synonym of
Goniopholis simus. The holotype is an almost complete cranium, referred to as DORCM G97, missing the anterior portion of the rostrum. The skull was found from either Swanage or the
Isle of Purbeck (hence the species name), although the exact locality from which the skull originated is not specified by the author of the original description. This material was also once referred to
Macrorhynchus. The author of the 1888 description considered
S. purbeckensis an intermediate form between
Steneosaurus and
Teleosaurus. This has been considered a junior synonym of
P. purbeckensis by both Salisbury
et al. (1999) and Salisbury (2002). In an SVPCA abstract, Smith
et al. (2016) noted that
Pholidosaurus purbeckensis is not congeneric with the type species, and instead is closely related to
Fortignathus and members of
Dyrosauridae. ==Classification==