Pseudocheirus is a genus of ringtail possums (family Pseudocheiridae). It includes a single living species, the common ringtail possum (Pseudocheirus peregrinus) of Australia, as well as the fossil Pseudocheirus marshalli from the Pliocene of Victoria.[1]
Other species have previously been included in this genus. Most other ringtails—the lemur-like ringtail (Hemibelideus lemuroides), the rock-haunting ringtail (Petropseudes dahli), and the various species of Pseudochirulus and Pseudochirops—were classified in Pseudocheirus until the 1980s or 1990s.[2] A second ringtail from the Victorian Pliocene, Petauroides stirtoni, was originally named as a Pseudocheirus, but is now considered to be more closely related to the greater glider (Petauroides volans).[3]
The genus was erected by William Ogilby in 1837, the same author later using then correcting the spelling Pseudochirus that is now regarded as a nomenclatural synonym used in error by authors such as Oldfield Thomas.[4]
Taxonomic opinion favours treatment of the western population, Pseudocheirus peregrinus occidentalis, as a separate species (Pseudocheirus occidentalis), though the contradictory evidence from current studies have prevented this recommendation being published.[5]