[Distribution of the species-specific lifespan in various taxonomic animal groups]

A distribution of specific lifespan has been studied in different taxonomic groups of animals. A positive skewness has been observed in animal kingdom as well as in smaller taxonomic groups. The skewness is higher in groups with relatively short lifespan (Insecta, Rotatoria, Mollusca). A coefficient of variation and excess is also higher in the above groups. A comparison of these coefficients with paleontological age of the group allows to conclude that evolutionary progress of animals was accompanied by the increase in skewness, variation and excess of specific lifespan distribution.