I asked myself the same question, and went for the PNG version because it is on transparent background which makes it more useful in my opinion (for the purposes I can imagine, though there are probably many that I don’t) and that I could not identify any loss of quality between the two versions. That being said, the JPG one is valuable as well. Jean-Fred (talk) 13:22, 24 July 2011 (UTC)[reply]
Comment If a gallery exists, please use that in the scope and add the nominee to the gallery (for taxa, always create the gallery with taxo info if it doesn't exist). W.S.15:53, 24 July 2011 (UTC)[reply]
Ah, ok, I did not know about that. I see Archaeodontosaurus just dit it (thanks!). I’m a bit surprised though, this means we actually encourage to use galleries? Well, I guess this is not the place to have a debate on that . Jean-Fred (talk) 07:03, 28 July 2011 (UTC)[reply]