So, was the little ancient rock...

Always wondered what that little rock in chapter 105 was, as ancient as the planet itself, and so small too. Could it be a piece of/or phos from the previous time cycle? Like, the place where the phos comet could end up falling?

On chapter 108, phos is colored darker at the end and also seems to be a similar size, I could be wrong, but I don't think putting a really old organism there is just a detail, Ichikawa doesn't plan for nothing