Table 2 Phylogenetic clustering (D) of mass extinctions summarized over 1500 time-scaled trees.

Mean P values indicate whether extinction scenarios deviate significantly from models of random (D ≥ 1) versus BM phylogenetically structured extinction (D ≤ 0); statistically significant values indicate that the model can be rejected. The number of trees out of a sample of 1500 for which random and phylogenetic structuring models can be rejected is also given.

Extinction
scenario
Mean extinct
taxa
Mean extant
taxa
Mean DSD of DMean P value,
random
model
N trees
rejecting
random
model
(P < 0.05)
Mean P value,
BM model
N trees
rejecting BM
model
(P < 0.05)
Ordovician:
end-Katian
14.94142.7392.2440.7230.92880.0111436
Ordovician:
end-Katian
and
end-
Hirnantian
17.13242.5431.9800.9070.95860.0091446
Devonian:
end-Givetian
3.3613.989−36.5771302.1650.536200.318219
Devonian:
Givetian-
Frasnian
4.6072.914−0.27126.8070.36570.48092