Labels:text | screenshot OCR: 430 MYA HALYSITES TUBES OF CORAL 0 NCE FOUND worldwide, Halysites was a coral that lived in warm, shallow waters in the Ordovician and Silurian Periods. Each tiny individual had a saclike body, with a mouth and tentacles. Groups built tubes 5 cm (2 in) long, which stuck together and formed coral reefs. CORAL COLONY Each tube of coral was created by the creature that once lived in it. RIBBON-LIKE FORMATION