Data from: Marine animal diversity across latitudinal and temperature gradients during the Phanerozoic

The latitudinal biodiversity gradient (LBG) is a fundamental biological
pattern seen across taxa and ecosystems today, but its drivers remain
uncertain despite intense theoretical and empirical study.
Palaeontological studies may add valuable evidence from diversity
distributions during intervals when Earth system configurations were
different from today, including potential analogues of future climate
regimes. However, accurately characterising these distributions is
challenging because the geographic scope of fossil record coverage varies
through time, introducing biases that have not been quantified by most
previous studies. Here, we attempt a comprehensive documentation of
latitudinal biodiversity distributions for marine invertebrates through
the past 540 million years, explicitly accounting for regional variation
in diversity and sampling. We demonstrate large uncertainties when using
current fossil data at this scale. Nevertheless, some signals are
detectable. We show that marine animal biodiversity declined with
increasing palaeolatitude and with decreasing temperature during at least
some intervals from the Permian onwards (298.9 Ma). Additionally, we find
that the LBG was shallower, on average, when Earth’s climate was hotter,
although this signal is weak. We also document a strong, systematic bias
due to intense sampling of the fossil record in North America and
especially Europe, which may have led previous studies to incorrectly
infer a mid-latitude diversity peak during hot intervals of Earth history.
Our results provide a baseline for what current fossil databases might
tell us about Phanerozoic LBGs of marine animals, and suggest that
quantitative consideration of uncertainties will be central to advancing
knowledge of geographic variation in diversity through Earth’s history.