Difference between revisions of "The oldest fossil foraminifera"
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| − | “Discussions concerning the appearance of skeletonization near the base of the Cambrian [about 550 Ma (million years ago)] are often restricted to metazoans and take little account of the acquisition of hard parts by protists at the same time. For example, hypotheses relating the evolution of skeletonization to increases in body size and to detoxification of excess calcium in metazoans do not apply to protists and hence are weakened by the appearance of testate protists in the Early Cambrian. However, this appearance is not inconsistent with the hypothesis, applicable to both metazoans and protists, that the initial function of skeletons was to protect the organism, primarily against predation. '''The presence of agglutinated foraminifera in the Lower Cambrian, probably Atdabanian Stage-equivalent strata, of the Taoudeni Basin, West Africa is reported here.''' These specimens extend considerably the known geologic range of several genera, they represent the earliest known unequivocal foraminifera, and they further remind us that protists as well as metazoans should be considered in accounting for the origin of skeletalization.” After [[Bibiography Culver (1991, p. 689)]] | + | “Discussions concerning the appearance of skeletonization near the base of the Cambrian [about 550 Ma (million years ago)] are often restricted to metazoans and take little account of the acquisition of hard parts by protists at the same time. For example, hypotheses relating the evolution of skeletonization to increases in body size and to detoxification of excess calcium in metazoans do not apply to protists and hence are weakened by the appearance of testate protists in the Early Cambrian. However, this appearance is not inconsistent with the hypothesis, applicable to both metazoans and protists, that the initial function of skeletons was to protect the organism, primarily against predation. '''The presence of agglutinated foraminifera in the Lower Cambrian, probably Atdabanian Stage-equivalent strata, of the Taoudeni Basin, West Africa is reported here.''' These specimens extend considerably the known geologic range of several genera, they represent the earliest known unequivocal foraminifera, and they further remind us that protists as well as metazoans should be considered in accounting for the origin of skeletalization.” After [[Bibiography|Culver (1991, p. 689)]] |
