Figure 3
From: Breeding Young as a Survival Strategy during Earth’s Greatest Mass Extinction
Differences in population structure, life expectancy, age at reproductive maturity and fecundity.
(a) Body size distributions based on basal skull length (%BSLmax) showing distinct differences between Permian (blue) and Triassic (red) species of Lystrosaurus (see text and Supplementary Material for results of chi-squared analysis comparing frequency distributions of larger and smaller individuals across taxa). (b) Modelled size class distribution under six scenarios: Early breeding (triangles) results in the observed Triassic pattern (i.e. fewer % of larger individuals). Blue, long life; Red, short life. Circles, late breeding and low fecundity; Triangles, early breeding, low fecundity; Squares, late breeding, high fecundity. Results are simulated stable size class distributions resulting from matrix model projections, presented as means with 95% confidence intervals over 1 000 permutations of each model condition. (c) Extinction rates for the six scenarios. Early-breeding taxa have the lowest extinction rates. log Wx, proportion of individuals at size class X at stable size distributions; Pext, probability of extinction.
