Paraboloid colony bases in Paleozoic stenolaemate bryozoans



Dendroid stenolaemate bryozoan colonies with paraboloid bases developed initially in the same manner as stenolaemate colonies with broadly encrusting bases. Their unique shape is related to the narrowly cylindrical shape of the encrusted surface (algal stipe?) and to radially differentiated rates of growth from the point of colony origin. The colony shape is interpreted as an adaptation to unconsolidated substrates in relatively quiet though not necessarily deep water.