Table 1.

Demographic ageing parameters for four species of tyrannosaur, wandering albatross, hippopotamus and African elephant. (Data for the albatross and mammals are from Ricklefs 1998).

species	mass (kg)	m0	α	β	ω	PS
Daspletosaurus torosus	1728	0.0054	1.00×10−08	5.42	0.0566	0.880
Gorgosaurus libratus	1234	0.0250	1.00×10−08	5.89	0.0691	0.641
Tyrannosaurus rex	5551	0.0066	9.93×10−09	5.64	0.0622	0.877
Albertosaurus sarcophagus	1218	0.0036	2.98×10−04	2.24	0.0819	0.943
Diomedia exulans	7.65	0.013	6.64×10−05	2.01	0.041	0.672
Hippopotamus amphibius	1200	0.030	5.28×10−06	3.00a	0.048	0.460
Loxodonta africana	6607	0.040	1.70×10−06	3.00a	0.036	0.262

^aβ fixed.