Close examination of the remarkable Heliolites, or 'sun
stone' fossil, shows that it appears to be covered with circles
surrounded by radiating lines, bearing a striking
resemblance to tiny, rayed suns. In this genus of
extinct tabulate corals (see Favosites above), the
tiny 'suns' are, in fact, formed by the skeletal
ribs, or septa, in the chambers inhabited by the
polyps that built the coral skeleton. Heliolites
formed a major part of Mid-Palaeozoic
tabulate reef communities, and it is
often found in association with
Fauosites and Halysites.
Right. Heliolites formed large, piltow-tike
structures that contnbuied greatly to
the reefs that existed 400 mtttton
years ago. These would have
provided shelter for a veneiv of
different pnmitive fish,
molluscs such as ammonOlds,
and other creatures, as well as
food, as predators tried 10 nibble
the sett-bodied coral polyps from their