Burrowing of the lingulid brachiopod Glottidia pyramidata: its ecologic and paleoecologic significance

摘要: Contrary to popular assumption, the pedicle of Glottidia is not its principal burrowing organ. The brachiopod props itself up with and enters sediment valves leading, anterior end first. trails behind. Burrowing accomplished by cyclical valve motions: rotary, sliding, gaping movements are used. Rapid closure ejects water from mantle cavity loosen sediment. lateral setae convey mucus-bound sand posteriorly (upwards). X-radiography shows that burrows U-shaped: in a few hours, animal reappears feeding position pointing out extending down into burrow. This process explains substrate preferences lingulids. thick. closely spaced adapted for burrowing. spacing between individuals increased, suggesting competition food.