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. 2012 Dec 19;7(12):e51925. doi: 10.1371/journal.pone.0051925

Table 2. Exploration of body size distributions for major vertebrate groups, dinosaur clades, time periods and formations.

Comments Category Skewness Location of modes on x-axis of body size distribution Lilliefors D p value
Major vertebrate groups Dinosaurs −0.758 6.3 0.105 <0.001
(see Figure 2) Birds 0.837 1.3 4.6 5.2 0.091 <0.001
Reptiles 1.077 0.9 6.1 0.109 <0.001
Amphibians 1.140 0.0 2.8 4.2 0.082 <0.001
Fish 0.180 −1.6 1.5 1.9 2.4 0.021 <0.001
Extant Mammals 0.906 1.5 4.8 0.118 <0.001
Pterosaurs 0.226 3.0 4.5 0.117 0.084
Extinct Mammals 0.333 2.0 4.7 0.089 <0.001
Major dinosaur clades Ornithischia −0.909 6.1 0.157 <0.001
(see Figure 4) Sauropodomorpha −1.501 7.1 0.161 <0.001
Theropoda −0.305 5.3 0.084 0.076
Major time periods Late Triassic −0.432 4.3 5.6 6.4 0.195 0.029
(see Figure 5) Early Jurassic 0.071 4.1 0.143 0.354
Middle Jurassic −1.369 6.6 0.182 0.015
Late Jurassic −1.294 2.3 6.0 7.2 0.142 0.008
Early Cretaceous −0.089 3.8 6.0 0.114 0.052
Late Cretaceous −0.950 2.3 3.6 4.7 5.7 6.5 0.119 <0.001
Major Formations Morrison −0.558 7.2 0.223 0.003
(see Figure 6) Dinosaur Park −0.697 4.2 6.5 0.170 0.070

Values are given for skewness of the distribution, location of modes in the distribution, Lilliefors D statistic and the p value showing significant difference from a normal distribution.