In particular, gap distributions are better compared with extinction and origination rates rather than with total diversity estimates.
Consequently, analytical techniques assessing the completeness of the fossil record are critical to understand the meaning of Lazarus taxa. Interpreting the Lazarus effect is an asymmetrical procedure because the biological alternative is only favoured when the stratigraphic one cannot be documented. The Lazarus phenomenon is a rare, possibly under-reported condition that happens when someone who seems to be dead shows signs of life again, typically several minutes after health workers stop. In addition, the sampling intensity is an external factor commonly linked with both the stratigraphic and the biological alternatives. Differences between these two biological explanations seem to be more rhetorical than substantiated. The Lazarus phenomenon is described as delayed return of spontaneous circulation (ROSC) after cessation of cardiopulmonary resuscitation (CPR). The latter option includes two traditional hypotheses implying existence of refugia and post-extinction low population diversity. The adequacy of the fossil record is the key for interpreting the Lazarus pattern: either Lazarus taxa reflect the incompleteness of the fossil record (the ‘stratigraphic alternative’), or they illustrate genuine extinction-linked phenomena (the ‘biological alternative’). While several authors regard the Lazarus effect as the temporary disappearance of taxa from the fossil record in any given time interval, many others consider the Lazarus effect as a pattern restricted to mass extinction episodes. Likewise in conservation biology and ecology, it can refer to species or populations that were thought to be extinct, and are rediscovered. The many definitions and interpretations associated with the ‘Lazarus effect’ have considerably confused this notion. In paleontology, a Lazarus taxon (plural taxa) is a taxon that disappears for one or more periods from the fossil record, only to appear again later.
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