Tessellationsshadern sounds like plural to me, unlike Essensmarken which sounds like genitive. Of course this would depend on the gender of Tessellation.
It's supposed to sound like genitive (and does to me). Tesselation would be feminine, of course, just like any other German word ending in "-tion" (can't think of a counter example).
Die Tesselation, plural die Tesselationen... Right?
Either way, do what you see fit. :)
Will do ;)