Is the skeleton meditation of Buddhist origin? I came across a skeleton meditation mentioned in this answer on this site, and I was interested because it supposedly grants interesting special abilities.

Googling it, I just found pages about something called white skeleton meditation, which I assume is the same thing (although according to guesswork on other forums it is either a Tibetan Buddhist type of meditation or a Taoist meditation but apparently NOT zen). Most sites that describe WSM talk of qi (because it "nourishes ones qi"), something I've never heard mentioned in a Buddhist context but I've heard very little. 

Wikipedia seems to have nothing on the subject, so what is the origin of skeleton meditation? Is it a Buddhist meditation? A skeleton meditation is mentioned in this little book by Pa Auk Sayadaw (which I suppose is the same as the meditation mentioned in the answer referenced above).

Did Buddha ever talk of/teach this meditation?
Yes it's a Buddhist teaching. Contemplation on a skeleton is called atthika-sanna in Pali. Buddha's teaching of this is in Atthikamahapphala sutta (SN 46.57), however, there's no English translation of this .This technique is commonly used by forest monks to overcome sensual desires. You can practice it with a real skeleton, a picture of it or visualizing a skeleton in mind.