Temporal calibration constraints used in the divergence time analyses.

aCalibrated node corresponds to the most recent common ancestral node of the listed taxa (see Fig. 1 for position of calibrated nodes). UK  =  United Kingdom; CALIF  =  California; ATL  =  Atlantic Ocean; IND  =  Indonesia; PAC  =  Pacific Ocean; DEN  =  Denmark; JAP  =  Japan.
bFossil or molecular estimates taken from the literature. Ma  =  millions of years ago.
cPriors used for temporal constraints. N  =  Normal(mean, standard deviation); E  =  Exponential(mean, offset); LN  =  Lognormal(mean, standard deviation, offset). Two analyses were performed: 1) the majority of temporal constraint priors were exponentially-distributed, and 2) those same nodes were instead described by lognormal priors; the remaining constraint priors (U and N) were not altered across analyses. See text for explanation.
dClosure of the Panamanian Isthmus.
eRhizosolenia-Corethron divergence are based on the estimated time of the abrupt increase in the C25 HBI alkene.
fFirst appearance of the genus Coscinodiscus in the fossil record.
gFirst appearance of the genus Melosira in the fossil record.
hFirst appearance of Synura uvella and Mallomonas insignis in the fossil record.
IFirst appearance of the genus Coccolithus in the fossil record.
jThe origin of haptophyte calcification.
kDates from fossil events in linearized tree [104].
lInferred molecular divergence between (Rhodophyta, Viridaeplantae) and the ingroup [46]. Also supported by the fossil Bangiomorpha[45].