Data from: How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model

The fossil record is a rich source of information about biological
diversity in the past. However, the fossil record is not only incomplete
but has also inherent biases due to geological, physical, chemical and
biological factors. Our knowledge of past life is also biased because of
differences in academic and amateur interests and sampling efforts. As a
result, not all individuals or species that lived in the past are equally
likely to be discovered at any point in time or space. To reconstruct
temporal dynamics of diversity using the fossil record, biased sampling
must be explicitly taken into account. Here, we introduce an approach that
uses the variation in the number of times each species is observed in the
fossil record to estimate both sampling bias and true richness. We term
our technique TRiPS (True Richness estimated using a Poisson Sampling
model) and explore its robustness to violation of its assumptions via
simulations. We then venture to estimate sampling bias and absolute
species richness of dinosaurs in the geological stages of the Mesozoic.
Using TRiPS, we estimate that 1936 (1543–2468) species of dinosaurs roamed
the Earth during the Mesozoic. We also present improved estimates of
species richness trajectories of the three major dinosaur clades: the
sauropodomorphs, ornithischians and theropods, casting doubt on the
Jurassic–Cretaceous extinction event and demonstrating that all dinosaur
groups are subject to considerable sampling bias throughout the Mesozoic.