A treasure map to search for past marine life

Fossils offer a glimpse into Earth’s distant past. They provide insights into extinct animals and plants, as well as past ecosystems. However, the fossil record is incomplete: Fossilization is rare, and only a small fraction of Earth’s organisms are preserved this way. In addition, geological strata from different eras must be accessible today for fossils to be found in them.

Our knowledge of past life is distributed unevenly across geological eras and geographic regions. Some eras and regions appear to be well-researched, with numerous fossils already found there. In contrast, we still know very little about others. Fossil excavations are extremely time-consuming and expensive, so it is important to focus efforts on areas likely to yield new information.

Mapping gaps in marine fossils

Thomas A. Neubauer of the Bavarian State Collections of Natural History (SNSB) and his colleague Mathias Harzhauser of the Natural History Museum in Vienna are providing researchers with a tool for that purpose.

In their study, the two paleontologists quantified the spatial distribution of all fossil finds of animals from shallow-water marine environments over the past 540 million years—and, for the first time, marked locations on a world map where fossil data is lacking.

The researchers searched the archives of the Paleobiology Database (PBDB). The PBDB is a major freely accessible database of fossil records and encompasses a large portion of published paleontological information.

The researchers mapped all marine shallow-water areas throughout Earth’s history that, according to the PBDB, contained fossil data. They also tracked historical trends in paleontological research on this habitat, documenting the rate at which research in specific regions has yielded new information over decades and centuries. The researchers cross-referenced this data with geological data from the Macrostat database.

The research is published in the journal Science Advances.

Older eras yield fewer surprises

The analysis revealed that the Mesozoic Era (about 252 to 66 million years ago) and the Paleozoic Era (about 539 to 252 million years ago) are particularly well-studied. Neubauer and Harzhauser do not expect any significant increase in information from fossil finds dating to 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 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 the relevant geological strata are accessible.

A guide for future excavations

“The fact that many regions of the Earth remain unexplored offers hope for valuable new discoveries,” says SNSB paleobiologist Neubauer. “But precisely because expanding the fossil record is quite challenging and progresses only slowly, our work can help researchers worldwide focus their efforts 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.”

Who’s behind this story?

Swati Mestri

Swati Mestri holds a bachelor’s degree in Electronics Engineering and has worked as a content editor since 2019. She has experience editing research documents across technology, health care, and materials science, and has a particular interest in technology and space.

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Robert Egan

Bachelor’s in mathematical biology, Master’s in creative writing. Well-traveled with unique perspectives on science and language.

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