There is a way.
At least I did it using
Anatomy software and a first frame of animated .gif.
I did cut movable parts of that frame and load them into
the Anatomy sprite tool. After that you can create your own sprite animation using textures of the .gif animation.
The bone-like system of the software really simlifies the work.
It takes appr 1 hour for me to animate walk and attack animations for any 2d static picture.
In my case just copying .gif to spritesheet was not enought because for any game you would need more than one action of your character. So I did find solution using this bone-oriented software.
Anatomy software:
http://spritetools.com/index.php/softwareYouTube tutorial:
http://www.youtube.com/watch?v=R6RdZiX0EAs&feature=youtu.beGood luck.