Fig. 1. Pione cf. vastifica spicules and erosion scars. (A) All three types of spicules. The longest one is a tylostyle. (B) An acantho microxea. (C) An acantho microrhabd. (D) Wall of sponge excavation in coral, covered with erosion scars. (E) A few erosion scars of different shapes. Of note are the projections in the center of some of them, where no substrate dissolution occurred. (F) A single erosion scar with a small projection in the middle. Signs of penetration beneath the projection are evident in its perimeter (arrowheads). Arrow indicates the area assumed to have been chemically removed.