Abundance of chondrichthyan genera through time

As of September 2019, the Florida Museum of Natural History (FLMNH) had a curated collection of 117,449 chondrichthyan specimens from Florida, spanning the Eocene through the Pleistocene. Herein, I evaluated the completeness of the chondrichthyan fossil record from Florida based on the FLMNH collection, while analyzing trends in taxonomic and ecomorphological diversity. At least 70 chondrichthyan taxa were recognized in the FLMNH collection, representing 10 orders, 26 families, and 42 genera; of which, 20 taxa represent first occurrences from Florida. A sample of 107,698 specimens was organized into 12 time bins to analyze taxonomic and ecomorphological diversity, with an expectation that diversity trends would correspond with global climate events (e.g., the Eocene-Oligocene Transition and the Middle Miocene Climatic Optimum). However, diversity trends were obscured by pervasive sampling bias, attributable to variable collection methods, research prioritizations, and regional lithologi...