The Eocene-aged Monte Bolca fossil site near Verona, Italy was one of the first lagerstatte to be discovered to science, and still has one of the most prominent vertebrate faunas of all Cenozoic lagerstatte. It has the highest fish diversity of all known Cenozoic fossil sites, with many fossils having extremely detailed preservation. In addition, a very high diversity of marine invertebrates & land plants and a small number of land vertebrates are also known.
The Monte Bolca complex comprises two major marine limestone localities, the Pesciara (where fossils are found in caves) and the Monte Postale site (where fossils are directly quarried). The Pesciara is thought to represent a marine structural basin dominated by planktivorous fish, with an anoxic environment at the bottom that led to excellent preservation of fossils. Meanwhile, the Monte Postale site is thought to represent a turbid coastal area surrounded by mangroves, seagrass meadows, and coral reefs, with poorer fossil preservation. In addition, a few small, slightly younger lignitic sites that preserve a Messel Formation-esque freshwater or brackish habitat are known nearby, which are the Purga di Bolca and Vegroni sites. These sites preserve terrestrial reptiles, freshwater plants, and freshwater/terrestrial mollusks, which are otherwise rare to absent from the complex.
Cartilaginous fishes.
Based on Marrama "et al", 2021:
Sharks.
An alleged specimen from Bolca of the otherwise Cretaceous shark "Mesiteia emiliae" has been found to actually originate from the Sannine Formation of Lebanon.
Ray-finned fishes.
Primarily based on Papazzoni "et al". 2014, with more recent taxa also added. Taxonomic order and arrangement based on "Eschmeyer's Catalog of Fishes" (2025):
Reptiles.
Based on Seghetti "et al", 2022:
Crocodilia.
A record of ""C." cf. "vicetinus"" that is now assigned to "Diplocynodon" is thought to actually originate from the Oligocene-aged Monteviale site, as opposed to Bolca.
Mollusca.
Gastropoda.
Based on:
Annelida.
The genus "Sthenelaites", formerly interpreted as a bristleworm, is now thought to represent a fossilized green algae in the Dasycladaceae.
Plantae.
Based on Massalongo (1859), though many taxa are form taxa, highly dubious or "nomina nuda", and/or use outdated taxonomy: