Secondary Calcification in the Foraminiferal Genus Globorotalia

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Science  29 Sep 1967:
Vol. 157, Issue 3796, pp. 1554-1555
DOI: 10.1126/science.157.3796.1554


Populations of four species of the planktonic foraminiferal genus Globorotalia from sediments in the Gulf of Mexico show the effects of secondary thickening of the test. Quantitative tabulation of the distribution of thin- and thick-walled specimens illustrates an abrupt and separate depth at which the thickening takes place for each species.