That's unexpected. I posted on the Smithsonian Zoo thread (Smithsonian National Zoo News 2020 [Smithsonian National Zoo]) but I'll repeat it here as well.
Basically, like everyone else on here, the only Virginia Opossums for which I am familiar with the appearance are the northern ones from the USA which, it turns out, are pretty different to the subspecies from the south of the range. There is a north-to-south range of colouration, so the northern animals tend to be white or grey with little or no pigment in the soft parts (tail and digits), while southern animals are much darker. In Mexico, where the distributions of the Virginia and Common Opossums overlaps considerably, they can be difficult to distinguish from one another because they are morphologically so similar and yet also both so variable in colouration.
I found a key to Mexican opossum species, and also checked out Fiona Reed's field guide, and the best distinguishing features of living animals are the cheek colour (always pure white in Virginia Opossum - easily seen in all the photos of the National Zoo's animal - but always yellowish or cream in Common Opossum) and the colour of the whiskers (a mix of black and white in Virginia Opossum - which can be seen in the better photos, including some on Zoochat - but all black in Common Opossum). I'd imagine it was these features that made somebody initially question the Common Opossum identity.
These features in addition to the genetic test make me perfectly happy to accept that the animal is a Virginia Opossum. I can still use the photo in the thread though, because it is of a different subspecies to the USA one already pictured.
