Table 2.

Summary of results for phylogenetic model fitting for archosauromorph and therapsid clades. Key as for table 1 except: r, decay rate for exponentially changing rate of evolution. Brownian motion (BM) with trend indicates an evolutionary trend, BM indicates significant variation but no trend, OU indicates evolution towards an optimum and early burst indicates exponentially decreasing evolutionary rate.

clade	n	Brownian motion with trend (BM+trend)		Brownian motion (BM)		stasis		Ornstein–Uhlenbeck (OU)		early burst (EB)
		A.W.	μ, σ², θ (log mm)	A.W.	σ² (log mm)	A.W.	θ, ω (log mm)	A.W.	α, ω (log mm)	A.W.	ω (log mm), r
Archosauromorpha	150	0.177	−0.001, 0.006, 2.079	0.422	0.006	0	2.300, 0.252	0.252	0.004, 0.006	0.149	0.006, 0
Dinosauromorpha	75	0.203	0.002, 0.006, 2.074	0.467	0.006	0	2.543, 0.169	0.172	0.002, 0.006	0.158	0.006, 0
Ornithischia	14	0.047	0.003, 0.005, 2.180	0.243	0.005	0.557	2.308, 0.087	0.109	0.044, 0.010	0.043	0.005, 0
Theropoda	24	0.163	−0.004, 0.007, 2.411	0.545	0.008	0.002	2.509, 0.151	0.145	0.003, 0.008	0.144	0.007, 0
Sauropodomorpha	28	0.079	0.006, 0.005, 2.265	0.103	0.005	0.616	2.844, 0.078	0.172	20.480, 3.177	0.029	0.005, 0
Pterosauria	12	0.003	0, 0.005, 1.596	0.022	0.005	0.861	1.674, 0.036	0.103	0.5000, 0.036	0.011	0.013, −0.050
Pseudosuchia	30	0.155	−0.005, 0.005, 2.403	0.304	0.005	0.003	2.321, 0.100	0.212	0.031, 0.008	0.326	0.009, −0.033
Aetosauria	7	0.003	−0.006, 0.005, 2.545	0.365	0.005	0.626	2.342, 0.072	0.004	50.000, 7.202	0.003	0.005, 0
Therapsida	138	0.036	−0.001, 0.011, 1.988	0103	0.011	0	2.009, 0.099	0.347	0.027, 0.012	0.514	0.016, −0.023
Anomodontia	50	0.160	0.009, 0.012, 1.857	0.418	0.012	0	2.060, 0.097	0.177	0.031, 0.014,	0.244	0.023, −0.062
Cynodontia	38	0.115	−0.003, 0.008, 1.859	0.347	0.008	0	1.807, 0.127	0.143	0.011, 0.009	0.395	0.011, 0.022
Therocephalia	19	0.048	0.015, 0.007, 1.900	0.202	0.007	0.524	1.933, 0.024	0.193	0.258, 0.013	0.032	0.007, 0
Gorgonopsia	37	0.000	−0.020, 0.014, 2.281	0.001	0.014	0.034	2.173, 0.025	0.964	0.534, 0.026	0	0.027, −0.064