Siliceous Sponge-Microbe Biotic Associations and Their Recurrence through the Phanerozoic as Reef Mound Constructors

Abstract

The association between mound-building, benthic microbial communities and siliceous sponges is characteristic of some reef mounds of Early Cambrian, Early-Middle Ordovician, Late Silurian, Late Devonian, Late Mississippian, Late Permian, Late Triassic and Late Jurassic age. Significant episodes of siliceous sponge-microbe reef mound construction, each lasting 5-15 Ma, generally recurred at intervals of approximately 70-100 Ma. Each was a time when thrombolite-forming and/or stromatolite-forming calcimicrobes flourished as constructors, and associated demosponges and hexactinellid sponges diversified as bafflers and binders, and even constructors on the reef mounds