English: Timeline (in million years before present, Ma) of major events in haptohyte evolution.

Age estimates of phylogenetic divergences and the timings of environmental adaptations are based on molecular clocks after Liu et al., 2010. Black boxes are average ages, colored bars show Bayesian 95% credibility intervals. The fossil record of the coccolithophores starts in the late Triassic and is illustrated as fossil morphospecies richness over time. Black line represents fossil coccolith morphospecies, gray line also includes nannoliths and other calcareous nannofossils, adapted after Bown et al., 2004. Numbers 1–7 depict main events: 1 = First fossil occurrence (FO) coccoliths; 2 = FO holococcoliths; 3 = FO biomarkers (alkenones); 4 = Cretaceous-Paleogene (K-Pg) mass extinction event (~66 Ma), 5 = Paleogene radiations; 6 = early Neogene radiations; 7 = Pliocene–Pleistocene radiations. Geological timescale abbreviations: Mesoprotero. = Mesoproterozoic era; Neoprotero. = Neoproterozoic era; Note horizontal scale change at 400–370 Ma within Cam-Dev. = Cambrian to Devonian periods; Neog. = Neogene period.

• Liu, H.; Aris-Brosou, S.; Probert, I.; de Vargas, C. A timeline of the environmental genetics of the Haptophytes. Mol. Biol. Evol. 2010, 27, 161–176.
• Bown, P.R.; Lees, J.A.; Young, J.R. Calcareous nannoplankton evolution and diversity through time. In Coccolithophores: From Molecular Processes to Global Impact; Thierstein, H.R., Young, J.R., Eds.; Springer: Berlin/Heidelberg, Germany, 2004; pp. 481–508.