I think it was more the "aura" the drawing gave off as I was working on it that led me to think of the subject as female. Originally this was going to be part of an actual "scene"...with the dimetrodon resting on the shade after a kill...sadly I never got around to it, partly because I'm still a bit stunted when it comes to drawing whole scenes in Paint. I invest so much time into the animal itself that by the time I finish it I lack the will to continue with drawing detailed trees, rocks etc., and this is why almost all of my drawings are of the animal against a simple solid colored background.
Yeah they are a neat creature for sure. Just to be Mr. Science Stickler though, Dimetrodon is not a dinosaur. It's a synapsid, and thus technically closer related to you and me then it is to T.rex or Triceratops.
As a minor note, what about the scutes on the toes and (at least what I think to be) scales on the body? AFAIK, synapsids never developed scales. But don't let that get you down, the drawing looks excellent and probably was a pain in the ass to complete.
Thanks! I'm going to do some looking into the synapsid skin issue before calling this one done then. Based on what I've read so far it sounds like a somewhat "scaly" skin was present in early synapsids in some form though. Mammals like opossums have kind of a "scaly" tail too, I'm going to research it further though. MS Paint drawings to have the benefit of being easy to edit.
We have skin impressions of ophiacodons, but they have belly scales that are actually analogous to fish scales, not reptile scales, that is, primitive gastralia. I would say that scales in armadillos and rodents gives an excuse to put scales in synapsids, because somewhere along the line, mammals must have retained the ability to grow scales. If the synapsids never had scales, you would expect no mammal to have scales, because the genetics for it would have possibly dissapeared.