Paleoecology and ecology of xenophyophores

Xenophyophores are large (several mm to 25 cm diameter), agglutinating protozoans, found primarily in the deep sea. Tests range from simple fans, discs or mudballs, to elaborately folded or reticulated forms, and often contain specific particle types or sizes. Xenophyophore densities are highest on sloped sediments associated with seamounts, continental slopes, canyons and trenches, and beneath productive surface waters. Most forms live as epibenthos on hard or soft substrates, feeding on surface deposits and suspended particles, but one endobenthic genus has been described. Modern xenophyophores enhance particle flux to the seabed, creating local regions of intense radiotracer and metazoan activity