Table 3.

Parameters estimated for the best models. (The best models and their parameters are listed for both the frequency of occurrences and geographic area trajectories for each group. These are also divided into results for all taxa with s.d.p.s of more than 10 and more than 20.)

	best model parameters
	nannoplankton			diatoms			radiolarians			planktic foraminifers
species—frequency of occurrences
all species	symmetric	μ	σ	symmetric	μ	σ	symmetric	μ	σ	symmetric	μ	σ
		0.67	1.09		0.31	1.08		0.64	1.11		0.33	1.06
s.d.p.>10	skewed	α	β	skewed	α	β	skewed	α	β	skewed	α	β
		1.82	0.89		1.67	0.86		2.04	0.90		1.62	0.92
s.d.p.>20	skewed	α	β	skewed	α	β	skewed	α	β	skewed	α	β
		1.76	0.84		1.79	0.84		2.24	0.86		1.75	0.93
species—geographic area
all species	symmetric	μ	σ	symmetric	μ	σ	symmetric	μ	σ	symmetric	μ	σ
		0.41	0.99		0.30	0.96		0.36	1.07		0.27	0.97
s.d.p.>10	skewed	α	β	symmetric	μ	σ	symmetric	μ	σ	skewed	α	β
		1.74	0.96		0.36	1.03		0.60	1.08		1.57	0.96
s.d.p. >20	skewed	α	β	skewed	α	β	skewed	α	β	skewed	α	β
		1.65	0.94		1.82	0.99		1.98	0.96		1.60	0.97
genus—frequency of occurrences
all genera	uniform	k		uniform	k		skewed	α	β	uniform	k
		0.29			0.25			1.92	0.90		0.29
s.d.p.>10	skewed	α	β	uniform	k		skewed	α	β	skewed	α	β
		1.57	0.84		0.23			1.87	0.87		1.31	0.76
s.d.p. >20	uniform	k		uniform	k		skewed	α	β	skewed	α	β
		0.26			0.23			1.89	0.88		1.29	0.75
genus—geographic area
all genera	symmetric	μ	σ	symmetric	μ	σ	symmetric	μ	σ	uniform	k
		0.37	1.03		0.20	1.03		0.33	1.05		0.20
s.d.p.>10	skewed	α	β	skewed	α	β	skewed	α	β	uniform	k
		1.52	0.90		1.65	0.91		1.71	0.92		0.17
s.d.p.>20	skewed	α	β	skewed	α	β	skewed	α	β	uniform	k
		1.52	0.87		1.75	0.92		1.82	0.94		0.17