Evolutionary History of Cambrian Spiculate Sponges: Implications for the Cambrian Evolutionary Fauna

• DOI: 10.2110/palo.2006.p06-089r
• Publication Date: 2008-03-03T15:53:49Z
• Authors: M. G. Carrera; J. P. Botting
• Keywords: 14. Life underwater; 01 natural sciences; 0105 earth and related environmental sciences

Broad-scale analyses of Cambrian spiculate sponges are scarce. The apparent differences between and Ordovician sponge faunas were included in Sepkoski's concept evolutionary faunas; these, regarded as minor contributors to the Paleozoic modern insignificant Evolutionary Fauna. More recent published occurrences inclusion archaeocyaths phylum Porifera, however, have altered our understanding significance among faunas. majority appear be segregated into two major associations: lower China, middle North America, primarily British Columbia Utah. main associations siliciclastic deposits from middle-to-deep muddy shelf basin environments, whereas orchoclad demosponges associated with shallow carbonate environments. Four aspects biology considered potential factors dictating distribution Cambrian: their trophic requirements, hydrodynamic constraints, possible biogeochemical sponge-sediment relationship. A series critical steps history occurred during interval Proterozoic-Cambrian boundary middle– late Ordovician. lower–middle a fauna, diverse monaxonid distinctive components. There was transitional fauna upper Cambrian–Lower Ordovician, lithistids dominating Hexactinellids began colonize nearshore settings this time. third interval, Middle–Upper corresponds Fauna, which is diversified several suborders families stromatoporoid sphinctozoan calcified experienced first radiation.