Absolute abundance and preservation rate of Tyrannosaurus rex

Estimating dinosaur abundance Estimating the abundance of a species is a common practice for extant species and can reveal many aspects of its ecology, evolution, and threat level. Estimating abundance for species that are extinct, especially those long extinct, is a much trickier endeavor. Marshall et al. used a relationship established between body size and population density in extant species to estimate traits such as density, distribution, total biomass, and species persistence for one of the best-known dinosaurs, Tyrannosaurus rex , revealing previously hidden aspects of its population ecology. Science , this issue p. 284