CRETACEOUS SEAS OF CALIFORNIA: OLD FOSSILS, NEW TRICKS

The Invertebrate Paleontology collection at the Natural History Museum of Los Angeles County (LACMIP) has received an NSF grant (NSF DBI 1561429) to improve the curatorial quality and digital accessibility of the museum’s extensive collections of Cretaceous marine invertebrates from California and Mexico (“Cretaceous Seas of California”). The descriptive taxonomy of these faunas has been intensively examined and published in 80+ publications and theses (Popenoe, Saul, Squires, et al.) over the past century. Yet, despite this effort, this body of literature is nowhere near exhaustive, and significant work remains to understand the broader, community-level dynamics (paleoecology, biogeography) of these faunas in time and space.

The Cretaceous Seas of California project aims to curate and digitize some 21,000 specimen lots and 126,000 specimens from 2,300 collecting localities, all of which were previously inaccessible (or nearly so) beyond the museum for decades. Other components of this project include compiling all relevant literature to facilitate internal and external consistency in the taxonomic and stratigraphic nomenclature applied to Cretaceous taxa and units. Importantly, many of these localities are now inaccessible, making the documentation, preservation, and public dissemination of their associated collections critical for future research endeavors.

Here we present results from a preliminary investigation on the paleoecology of five intensively sampled Upper Cretaceous faunas in the LACMIP collections that are directly relevant to the ongoing Cretaceous Seas of California curation and digitization project. The geologic units include the 1) Chatsworth, 2) Jalama, and 3) Ladd formations from southern California, and the 4) Chico and 5) Redding formations from northern California. Digitized collections data from these units permit us to analyze the community-level richness (alpha diversity) of multiple collecting localities, in addition to quantifying compositional variation (beta diversity) across environmental gradients and biogeographic areas during the Upper Cretaceous in California. This study thus constitutes one applied example of how high-quality digital collections data can be used to advance paleontological research.