This species is listed as Extinct because it has not been recorded in more than 100 years despite extensive surveys. The last known record was in the 1870s (Woinarski et al. 2019). Two types of probabilistic models to estimate the probability of extinction and the date of extinction of this species have been published (Fisher and Humphries 2024): a Nonparametric model (Solow and Smith 2005), and Threat & effort Cox Regression Survival model (Fisher and Blomberg 2012). Both concluded that this species is extinct with >90% probability.

Live-caught specimens and subfossil remains indicate that the Broad-faced Potoroo occurred on the northern Swan Coastal Plain, in the wheatbelt and in south coastal and southern near-coastal regions of Western Australia as far east as the South Australian border, on the Eyre and Yorke Peninsulas in south-western South Australia and on Kangaroo Island, South Australia (Butler and Merrilees 1971, Baynes 1987, McDowell et al. 2012, A. Baynes pers. comm. 2024).

Most of the early accounts of the Broad-faced Potoroo note that it was a rare species, consistent with the small number of specimens, compared with other species obtained by John Gilbert in the 1840s and Masters in the 1860s in southern Western Australia (Glauert 1950; see also Ride 1970). This is also consistent with the very small numbers of specimens held in modern mammal collections in museums. Its remains are not abundant in most cave deposits, with the single exception of a small cave at the western end of the Baxter Cliffs, Nullarbor Plain, where Masked Owls Tyto novaehollandiae may have been responsible for the accumulation (A. Baynes pers. comm. 2012).

However, the supposition of rarity, probably originating with Gould (1863), may be an artefact of poor sampling in the early days of European settlement, noting that John Gilbert collected mainly in areas where P. platyops did not occur. Glauert (1950) noted that Preiss, who collected in Western Australia just before Gilbert, acquired ‘several’ and that Masters collected four in the 1860s. The rodent Pseudomys occidentalis, shown by subfossil records to have occupied the same extensive range and probably the same habitat as P. platyops, was completely missed by 19th century collectors, but later found to be relatively abundant in suitable habitat (e.g., Kitchener and Chapman 1977).

The only information about habitat came from John Gilbert, who collected animals for John Gould. He wrote ‘All I could glean of its habits was that it was killed in a thicket surrounding one of the salt lagoons of the interior’ ('thicket' suggests dense shrubland, rather than wetland vegetation). Friend and Kitchener (2023) noted that its habitat use largely excluded forested areas.

Causes of extinction are presumed to be:
1. Predation by feral Cats Felis catus (severe, possibly catastrophic in combination with other threats): the Broad-faced Potoroo became extinct before the arrival of the Red Fox Vulpes vulpes in Western Australia, and is extinct on Kangaroo Island (South Australia) where there are feral Cats but no foxes. Cats were present throughout the range of this species by the 1890s (Abbott 2002, 2008). There is abundant evidence that feral Cats have a significant effect on medium-sized Australian mammals, including other species of Potorous (Radford et al. 2018) and have caused extinctions of other similar Australian mammals (Dickman 1996, Woinarski et al. 2014).
2. Exotic disease (severe, possibly catastrophic in combination with other threats): there is evidence for epizootic disease as the primary factor, but probably interacting with drought and predation by feral Cats as secondary factors, in decline and extinction of many mammal species in Western Australia; many of these declined before the arrival of Red Foxes; however, only parts of range would have been affected (Abbott 2006).
3. Inappropriate fire regimes (severe): fire regimes changed dramatically after European settlement; Aboriginal people used fire extensively and frequently to produce a mosaic of different-aged vegetation (Gammage 2011); this may have benefited this species.
4. Habitat degradation and resource depletion due to livestock and feral herbivores (severe): sheep grazing was widespread in parts of the Western Australian wheatbelt before clearing; however, it was limited to areas where there were no Gastrolobium spp., the browsing of which caused death in stock.
5. Habitat loss and fragmentation (moderate but only over small area of range): extinction occurred before widespread land clearing for agriculture in the Western Australia wheatbelt.

The species is extinct. It is listed as Extinct under Australian environmental law.