Biogeochemical evidence for dinoflagellate ancestors in the early cambrian
Dinoflagellates are single-celled organisms that reflect the ecological conditions in modern oceans and lakes. Ultrastructural data and molecular phylogeny suggest that they originated in the Neoproterozoic, yet dinoflagellate ancestors are classified only to the Middle Triassic ( approximately 240 million years ago). Examination of dinoflagellate-specific biological markers (dinosteranes and 4alpha-methyl-24-ethylcholestane) in concentrated microfossils with known morphology identified ancient dinoflagellate ancestors from the Early Cambrian ( approximately 520 million years ago).
J. M. Moldowan, Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115, USA. N. M. Talyzina, Department of Earth Sciences, Historical Geology and Paleontology, Uppsala University, Norbyvagen 22, S-75236, S.
JM
Moldowan
NM
Talyzina