  A major revision of the geological timescale was published in 2012. We
re-examine our past finding of a 27 Myr periodicity in marine extinction rates
by re-assigning dates to the extinction data used previously. We find that the
spectral power at this period is somewhat increased, and persists at a narrow
bandwidth, which supports our previous contention that the Nemesis hypothesis
is untenable as an explanation for the periodicity that was first noted by Raup
and Sepkoski in the 1980s. We enumerate a number of problems in a recent study
comparing extinction rates with time series models.
