1996/01/01 by Robert A. Fensome, R. A. Fensome, R. A. MacRae +6 · 5 citations
Earth and Planetary Sciences · #Paleontology and Stratigraphy of Fossils #Geological and Geophysical Studies #Geology and Paleoclimatology Research
paper · doi:10.1017/s0094837300016316
Dinoflagellates are a major component of the marine microplankton and, from fossil evidence, appear to have been so for the past 200 million years. In contrast, the pre-Triassic record contains only equivocal occurrences of dinoflagellates, despite the fact that comparative ultrastructural and molecular phylogenetic evidence indicates a Precambrian origin for the lineage. Thus, it has often been assumed that the dearth of Paleozoic fossil dinoflagellates was due to a lack of preservation or recognition and that the relatively sudden appearance of dinoflagellates in the Mesozoic is an artifact of the record. However, new evidence from a detailed analysis of the fossil record and from the biogeochemical record indicates that dinoflagellates did indeed undergo a major evolutionary radiation in the early Mesozoic.