On the age of fossil diatoms

Jadwiga Siemińska
2015 Acta Palaeobotanica  
The finding of fossil freshwater diatoms in late Cretaceous chert in Mexico suggests - together with all the discoveries of fossil freshwater diatoms known from positions older than the Cretaceous - that the extinct marine Cretaceous diatom taxa cannot be considered to be the oldest.
doi:10.1515/acpa-2015-0007 fatcat:y7nzbxyqrjgvlf4hdnmziwdwue