Data and code for: Diversity through space and time in the Upper Jurassic Morrison Formation, western USA

Understanding how biodiversity has changed through time and space is a
central aim of paleobiology. To elucidate accurate biodiversity patterns
in deep time, regional case studies, where sampling biases can be
minimized, are needed. The Upper Jurassic Morrison Formation of the
western USA crops out over 1.2 million km2 and covers 12 degrees of
latitude. It was deposited over a ~9-million-year time period and was home
to some of the most iconic dinosaurs. Utilizing a new, high-resolution
chronostratigraphic framework for the formation, tetrapod occurrences from
the Paleobiology Database were temporally and spatially mapped to examine
patterns of diversity change through time and space, and the geographic
ranges of taxa were examined to shed light on niche partitioning.
Latitudinally, diversity was found to peak in the center of the basin,
perhaps due to the availability of water resources. Diversity increased
over time in the Morrison Formation, and there is no evidence to indicate
a decline in diversity prior to the extinction of the fauna at the end of
the Jurassic. There appears to be some degree of geographic separation of
faunas in the Morrison basin, with southeastern and northwestern fauna,
albeit with a number of overlapping taxa. High-resolution climate models
paired with detailed sedimentological analysis could help to elucidate the
drivers of the patterns observed here.