Table 1.

The maximum body mass for all terrestrial mammals and for several orders increased linearly when generation time is accounted for

	Slope	Haldanes (× 10−6)	R2	P
Terrestrial maximum	1.59	7.14	0.97	1.17 × 10−5
Artiodactyla	0.74	3.34	0.90	3.33 × 10−5
Carnivora	0.65	2.94	0.74	6.87 × 10−4
Cetacea	3.25	14.60	0.83	1.70 × 10−3
Perissodactyla	2.13	9.57	0.98	9.70 × 10−3
Primates	0.39	1.77	0.78	1.46 × 10−4
Proboscidea	1.08	4.84	0.91	6.25 × 10−5
Rodentia	1.21	5.45	0.93	1.74 × 10−3

Slope for linear regression of M^0.259 vs. Age (Ma) for each group from their origin until their maximum (except for Cetacea, which is for the period of 31 Ma to the Recent). The average rate in haldanes was calculated using the mammalian scaling relationship of generation time with body mass (SI Appendix). These time intervals are plotted as points in Fig. 3B.