  A 62 Myr periodicity is superimposed on other longer-term trends in fossil
biodiversity. This cycle can be discerned in marine data based on the Sepkoski
compendium, the Paleobiology Database, and the Fossil Record 2. The signal also
exists in changes in sea level/sediment, but is much weaker than in
biodiversity itself. A significant excess of 19 previously identified
Phanerozoic mass extinctions occur on the declining phase of the 62 Myr cycle.
appearance of the signal in sampling-standardized biodiversity data, it is
likely not to be a sampling artifact, but either a consequence of sea-level
changes or an additional effect of some common cause for them both. In either
case, it is intriguing why both changes would have a regular pattern.
