Non-marine tetrapod extinctions solve extinction periodicity mystery

Based on their compiled data set of ten extinction episodes (four of which had no known extinction rates), Rampino et al. (2020) claimed a 27.5-My period in non-marine-tetrapod extinctions. I reassessed that claim using the Gauss–Vaníček spectral analysis (GVSA), which revealed spectra of extremely low fidelity (mostly << 1) dominated by the Earth’s axial precession, without 99%-significant periods, but with hundreds of 95%-significant periods unrelated to the extinctions and the claimed period.  Therefore, the data are physically nonsensical as far as any underlining cyclicity is concerned.  The analysis did not reveal the claimed period in any band, at either 99% or 95% significance, so the claimed period is a ghost due to intermediary astronomical forcing of highly gapped data sampled arbitrarily and processed with inapt techniques.  Thanks to the GVSA’s absolute accuracy, and insensitivity of non-marine data to the ocean-tidal component, I present remarkable proof that very long periods such as ~9 My (~27 My), ~11 My (~22 My), and ~33 My (~66 My), previously claimed in extinction data sets, have a common astronomical origin. They primarily arise due to the Earth’s axial precession, enforcing of which then is a must in paleostudies.