DO PERIODICITIES IN EXTINCTION—WITH POSSIBLE ASTRONOMICAL CONNECTIONS—SURVIVE A REVISION OF THE GEOLOGICAL TIMESCALE?
1. Adrian L. Melott (a)
2. Richard K. Bambach (b)
a. Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA
b. Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 121, Washington, DC 20013-7012, USA
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 in 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 & Sepkoski in the 1980s. We enumerate a number of problems in a recent study comparing extinction rates with time series models.