Friday mystery object #457 answer

Last week I gave you this skull from the collections of the Dead Zoo to have a go at identifying:

This specimen came to light during some research being carried out on carnivore bones by Dr George Argyros, a Professor visiting us from Emory & Henry College, Virginia. It was identified as Vulpes on the label, but both George and myself were doubtful.

The specimen’s spurious identification can be tracked back to when it was named in the Museum’s register as Vulpes fulva argentata or Silver Fox. This identification was assigned to the specimen when it was given to the Royal Zoological Society by N.H.P. Vickers in March 1900 (see page 127 of the monthly Irish Naturalist covering March 1900):

The Museum bought the specimen in skeletal form from the Royal Zoological Society of Ireland in 1903 and the name Silver Fox was kept until a later review of the taxonomic hierarchy in our database, which ‘corrected’ the name to Red Fox Vulpes vulpes.

However, this name change was not based on the morphology of the specimen. The characteristic lyre-shaped sagittal crest1 immediately made both myself and George think Urocyon and the small size of the specimen made both of us converge on an identification of Island Fox Urocyon littoralis (Baird, 1857) after independent bouts of measuring.

Image of Urocyon littoralis (Island Fox) by Pacific Southwest Region USFWS, 2015.

For those of you interested in seeing the size range parameters for Island Fox skulls, this PDF of the Mammalian Species description of Urocyon littoralis is very helpful indeed.

So I offer a hearty congratulations to everyone who spotted that this skull is from the genus Urocyon, although I think most people were thinking of the Grey Fox, Urocyon cinereoargenteus.

Image of Urocyon cinereoargenteus (Grey Fox) by California Department of Water Resources, 1993.

1It probably shouldn’t really be referred to as that, since it isn’t actually sagittal, except perhaps where the two ridges meet at the very back of the skull – but you know what I mean.

3 thoughts on “Friday mystery object #457 answer

  1. The one time I didn’t look harder for the species or check the size! I used to work on Santa Cruz Island, off the coast of Santa Barbara California and have seen many of these petite foxes. Each island has a separate subspecies. They faced rapid population decimation due to predation by non- native Golden Eagles. It’s a great conservation success story involving multiple organizations and species! How did one of THESE skulls get over THERE? And don’t tell me they swam.

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