Cohen, PheobeSchopf, J. W.Butterfield, N. J.Kudryavtsev, A. B.Macdonald, Francis2017-08-042011Cohen, P. A., J. W. Schopf, N. J. Butterfield, A. B. Kudryavtsev, and F. A. Macdonald. 2011. “Phosphate Biomineralization in Mid-Neoproterozoic Protists.” Geology 39 (6) (May 4): 539–542. doi:10.1130/g31833.1.0091-7613http://nrs.harvard.edu/urn-3:HUL.InstRepos:33717512The origin and expansion of biomineralization in eukaryotes played a critical role in Earth history, linking biological and geochemical processes. However, the onset of this phenomenon is poorly constrained due to a limited early fossil record of biomineralization. Although macroscopic evidence for biomineralization is not known until the late Ediacaran, we here report biologically controlled phosphatic biomineralization of scale microfossils from mid-Neoproterozoic (pre-Sturtian) strata of northwest Canada. Primary biological control on mineralization is supported by the identification of apatite in both chert-hosted and limestone-hosted specimens, the conspicuously rigid original morphology of the scale microfossils relative to co-occurring organic-walled cyanobacteria and acritarchs, and the microstructure of the constituent phosphate. Cell-enveloping mineralized scales occur in a wide range of extant protists, but the apparent restriction of phosphate scales to one modern taxon of green algae suggests a possible affiliation for these fossils. Documentation of primary phosphate biomineralization in Fifteenmile Group (Yukon Territory, Canada) microfossils greatly extends the known record of biologically controlled mineralization and provides a unique window into the diversity of early eukaryotes.en-USJournal Article10.1130/G31833.1