From the kitchen sink of the Triassic

Yes, it looks like that nasty old sponge that just scrubbed out the oatmeal pot. In truth, it is an even older and nastier sponge, a fossil from the Triassic-Jurassic platform carbonates of the Pelagonian continent (an outpost of Pangaea). We don't know what the Mesozoic inhabitants would have used it to clean up, but I predict it was something nastier than oatmeal.