24 Sept 2026
We know a lot about some geological eras, but very little about others. Palaeontologists have now identified areas around the world where previously unknown fossils are most likely to be found.
Fossils offer a deep glimpse into Earth’s history. They provide insights into extinct animals and plants as well as past ecosystems. However, the fossil record is also very incomplete: for an animal or plant to become a fossil at all is a rare coincidence, and only a small fraction of Earth’s organisms are actually preserved in this way. In addition, geological strata from different geological eras must be accessible today in order for fossils to be found in them at all.
Our knowledge of past life is distributed very unevenly across geological eras and geographic regions. Some geological eras and regions appear to be well-researched: numerous fossils have already been found there. In contrast, we still know very little about other geological eras and regions. Fossil excavations are extremely time-consuming and expensive—therefore, it would be important to focus efforts on areas promising new information.
Dr. Thomas A. Neubauer, from the Department of Paleontology and Geobiology at LMU and the Bavarian State Collections of Natural History (SNSB), and his colleague Professor Mathias Harzhauser of the Natural History Museum in Vienna are now providing researchers with a tool they can use directly for this purpose. In their study, the two paleontologists quantified the spatial distribution of all fossil finds of animals from shallow-water ocean environments over the past 540 million years—and, for the first time, marked the locations on the world map where fossil data is lacking.
Natural history collections such as the Bavarian State Collection of Paleontology and Geology in Munich are archives of biodiversity that also preserve material from regions that are often still unexplored. | © SNSB / Karina Hagemann
The researchers searched the archives of the Paleobiology Database (PBDB). The PBDB is the world’s most important freely accessible database for fossil records and encompasses a large portion of the published paleontological information. The researchers mapped all marine shallow-water areas throughout Earth’s history that, according to the PBDB, contained fossil data. In addition, the scientists tracked historical trends in paleontological research of this habitat: They documented the rate at which research in specific regions has actually yielded new information over the past decades and centuries. The researchers cross-referenced this data with geological data from the Macrostat database.
The analysis revealed that the Early Mesozoic (approximately 252 to 66 million years ago) and the Palaeozoic (approximately 539 to 252 million years ago) are particularly well-studied. Neubauer and his colleague do not expect any significant increase in information from fossil finds in these periods in the near future. The fossil record is least complete in Earth’s more recent history: despite an already rich body of evidence, the researchers’ analyses indicate that many more finds are still expected from the shallow-water marine deposits of the Cenozoic Era (beginning 66 million years ago). To improve our understanding of this period, the researchers identified areas around the globe where fossils of previously unknown species are likely to be discovered—and where such discoveries are indeed possible because the relevant geological strata are accessible.
“The fact that many regions of the Earth remain unexplored offers hope for valuable new discoveries,” says Neubauer. “But precisely because expanding the fossil record is quite challenging and progresses only slowly, our work can help researchers worldwide to focus their research specifically on these still largely unexplored areas. We provide a valuable guide for planning future projects and excavation campaigns. The same applies to the examination of existing museum collections awaiting scientific analysis. Through sensible prioritization, we can fill gaps in the fossil record strategically.”
Thomas Neubauer & Mathias Harzhauser: Staking out the frontiers: the limits of the metazoan shallow marine fossil record. Science Advances 2026.