concept

Damuth's rule

The ecologist John Damuth found in 1981 that population density falls off with body mass to roughly the power of minus three-quarters: the larger the animal, the fewer per square kilometre, because the energy available in a landscape is finite and a large body is expensive to run. The relationship holds across four orders of magnitude of mass. For paleontology the consequence is severe: the biggest, most spectacular animals were already the rarest, so the fossil record necessarily under-records them most.