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Researchers at the Bavarian State Collection for Natural History (SNSB) and the Natural History Museum Vienna have created a global map of shallow marine animal fossils spanning 540 million years. Published in the journal Science Advances, the study identifies the regions and periods where new species are most likely to be discovered, and those where research is already widely conducted.
An Incomplete Fossil Record
Fossils open a window onto the animals, plants and ecosystems of the past. Yet they tell only part of the story of life. Fossilisation is a very rare phenomenon: only a tiny fraction of the organisms that have lived on Earth have left a trace. And even when a fossil survives, it can only be discovered if the rock containing it is accessible today.
Our picture of prehistoric life therefore has vast gaps. Some geological periods and some regions have yielded fossils in abundance, providing detailed knowledge of ancient environments, while others remain largely unexplored. Excavations require considerable time and resources, so knowing where to look can make a real difference in uncovering new evidence of ancient life.
Five Hundred and Forty Million Years Mapped
To develop their tool, Thomas A. Neubauer of the Bavarian State Collection for Natural History and Mathias Harzhauser of the Natural History Museum Vienna analysed the geographic distribution of discoveries of animals that inhabited shallow marine environments over the last 540 million years. For the first time, they also mapped the regions where fossil information is lacking.
The data come from the Paleobiology Database, a freely accessible resource that brings together a large share of the world's palaeontological publications. The researchers reconstructed where these fossils have been documented and measured, over several decades and centuries, how often investigations in each region produced new information. They then cross-referenced these results with the Macrostat geological database to assess where suitable rock formations could fill gaps in the record.
An Imbalance in Our Knowledge
The analysis reveals a surprising imbalance. The early Mesozoic (roughly 252 to 66 million years ago) and the Palaeozoic (roughly 539 to 252 million years ago) have already been studied in depth. According to the authors, new discoveries from these periods should not significantly advance scientific knowledge in the short term.
The greatest opportunities lie instead in recent geological history. The Cenozoic, which began 66 million years ago, has already yielded much evidence, yet its shallow marine deposits may still hold considerable potential. It is therefore towards this era that prospecting efforts could bear the most fruit.
A Map to Guide Future Expeditions
The researchers identified, around the world, places where unknown fossil species are highly likely to be found. These are also locations where suitable geological layers are exposed or accessible, a prerequisite for any real discovery.
The approach could thus help palaeontologists plan more productive expeditions and make better use of limited resources. Rather than multiplying campaigns in regions already thoroughly combed, they can concentrate their efforts on little-explored areas, where the potential for new discoveries is greatest.
Museum Collections to Re-examine
The map can also guide the study of museum collections still awaiting scientific analysis. As Thomas A. Neubauer notes, "judicious prioritisation allows us to strategically fill the gaps in the fossil record". Palaeontologists thus have a tool for dividing their efforts between fieldwork and museum storerooms.
Frequently asked questions
What is the fossil record?
The fossil record refers to the body of fossils known and catalogued by scientists. It is incomplete, because fossilisation is rare and many rocks containing fossils are not accessible today. This study aims precisely to identify the areas where the record has the greatest gaps.
Which geological periods have been studied the most?
According to the researchers, the Palaeozoic and the early Mesozoic have already been the subject of numerous studies. New discoveries from them would therefore yield less information than from the Cenozoic, where shallow marine deposits still offer significant potential.
Where can marine fossils be found in France?
France has many fossil-bearing sites, notably in ancient and recent marine formations. Amateurs should, however, check with the competent authorities before any prospecting, as some deposits are protected.
Where can the fossil data used in the study be consulted?
The researchers used the Paleobiology Database, a freely accessible database that brings together a large share of the world's palaeontological publications. It allows fossil occurrences to be consulted by period and by region.
Sources
Original summary written with the help of artificial intelligence from the sources cited, checked automatically, then translated from the French original. Information and quotations belong to their authors. Read the French original.
