Test Fusion in Adult Foraminifera: a Review with New Observations of an Early Eocene Nummulites Specimen.


In foraminifera, so-called "double tests" usually arise due to abnormal growth originating mainly from twinning, but may also be caused by irregularities in the early chambers and by regeneration after test injury that modifies the direction of growth. A fourth cause of double tests has only rarely been reported: the fusion of the tests of two adult… (More)