“Calcareous red algae have been important components in reefal facies since the Mesozoic … we report a reef-building community dominated by Parachaetetes, a genus of solenoporacean red algae, overgrowing uppermost Permian sponge reefs in Cili (Hunan Province, South China)… Although the biodiversity of this community is far lower than that in modern reefs, the association of red algae and rugose corals shares several attributes with the coral–coralline algal communities of modern tropical reefs…this is the oldest site where crustose red algae played a dominant role in reef construction. Want to read more?!