Fig. 8From: Late Tremadocian (Early Ordovician) reefs on the Yangtze Platform, South China, and their geobiological implications: a synthesisGrowth styles of the bryozoan reefs in the Huanghuachang section. a Lithistid sponge-bryozoan reefs, showing lithistid sponges (Sp) occurred firstly on the bioclastic limestones (BL) (arrow heads showing the bottom of the reef); b Bryozoan reefs, showing bryozoans developed directly on the bioclastic limestones (BL); c Close-up of the lithistid sponge-bryozoan reefs, showing the downwards growth of bryozoans (arrows showing the outline of the reef); d Close-up of the bryozoan reefs, showing the upward growth of bryozoans (arrows); e Photomicrograph of lithistid sponge-bryozoan reef, showing bryozoans (Br) encrusted on the lithistid sponges (Sp); f Photomicrograph of bryozoan reefs showing zooidal chambers of bryozoans. The coin diameter = 2 cm; The hammer length = 282 mmBack to article page