A 27.5-My underlying periodicity detected in extinction episodes of non-marine tetrapods

ABSTRACT

Non-marine tetrapods (amphibians, reptiles, birds and mammals) have apparently experienced at least 10 distinct episodes of intensified extinctions over the past 300 My. Eight of these ten non-marine extinction events are concurrent with known marine-extinction episodes, which previously yielded evidence for an underlying period of ~26.4 to 27.3 My. We performed circular spectral analysis and Fourier transform analysis of the ages of the ten recognised tetrapod-extinction events, and detected a statistically significant (99% confidence) underlying periodicity of ~27.5 My. We also find that the eight coeval non-marine/marine-extinction pulses all occurred at the times of eruptions of Large Igneous Provinces (LIPs) (continental flood-basalts and oceanic plateaus), with potentially severe environmental effects. Three of these co-extinction episodes are further correlated with the ages of the three largest (≥100-km diameter) impact craters of the last 260 My, which are also apparently capable of causing extinction events. These findings suggest that global cataclysmal events with an underlying periodicity of ~27.5 My were the cause of the coordinated periodic extinction episodes of non-marine tetrapods and marine organisms.

KEYWORDS:

• Non-marine tetrapod extinctions
• periodicity
• Large Igneous Provinces
• impacts

Acknowledgments

The research was partly funded by a New York University Research Challenge Grant to MRR. We thank Mike Benton and three anonymous reviewers for comments. The computer programs used for statistical analyses in this paper are available from the authors.

Author contributions

Rampino conceived the idea behind the paper and compiled the data. Caldeira and Zhu performed the statistical analyses. All three co-authors analyzed the results and Rampino wrote the paper.

Disclosure statement

The authors declare no competing interests.