470 Million-Year-Old Fossils Convey Prehistoric Climate History

A pair of amateur paleontologists recently dug up an extensive collection of fossils in southern France, revealing how species tried to escape prehistoric global warming.

By Jack Knudson
Feb 9, 2024 9:30 PMFeb 9, 2024 9:34 PM
Cabrières Biota
An artistic reconstruction of the Cabrières Biota (Credit: Christian McCall)


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As the world gears up for an inevitable spike in temperatures over the coming decades, a newly found deposit of fossils might provide insight on the future actions of modern species.

"The distant past gives us a glimpse of our possible near future," said Jonathan Antcliffe, researcher at the University of Lausanne and co-author of the study, in a press release.

Two paleontology enthusiasts came across the fossil site in Montagne Noire, a mountain range in southern France, where they unearthed over 400 fossils of various ancient fauna. The fossils appeared to be in near-perfect condition; they consisted of not only shell-like components, but also rare softer features like digestive systems and cuticles.

These remains belong to species that lived during the Lower Ordovician period, around 470 million years ago. Researchers at the University of Lausanne in Switzerland have now taken a comprehensive look at the fossils and published their results in Nature Ecology & Evolution.

What Ancient Species Did Researchers Find?

Multiple types of species represented the fossil deposit, now known as the Cabrières Biota. Present at the site were arthropods (animals that have an exoskeleton and molt, like millipedes and shrimps), cnidarians (jellyfish and corals) and a large number of algae and sponges. 

All of these species were once located close to the South Pole; the biodiversity displayed at the site could indicate that it was a haven for species that migrated south to avoid the temperatures ramping up further north.

"At this time of intense global warming, animals were indeed living in high latitude refugia, escaping extreme equatorial temperatures," said Farid Saleh, researcher at the University of Lausanne and first author of the study, in a press release. 

The amateur paleontologists who found the deposit, Eric Monceret and Sylvie Monceret-Goujon, also expressed their enthusiasm.

"We've been prospecting and searching for fossils since the age of twenty," said Eric Monceret in a release.

"When we came across this amazing biota, we understood the importance of the discovery and went from amazement to excitement," added Sylvie Monceret-Goujon.

Further research will help better understand the internal and external anatomy of the organisms. For now, it seems that the history of these species and their reaction to warming temperatures may provide valuable insight in assessing future climate implications. 

Read More: What Are Fossils and Where Are They Found the Most?

What Occurred During The Ordovician Period? 

The Ordovician Period started approximately 485 million years ago, after the end of the Cambrian Period. The transition between these two periods entailed a wipeout of nearly half of all species, referred to as the Cambrian-Ordovician extinction event.

The mass extinction transpired as a result of drastic environmental changes, including depletion of oxygen in the ocean and increased volcanic activity. In addition, environments became extremely sulfidic, restricting nutrient supplies. 

However, an incredible turnaround followed at the start of the Ordovician; upwelling brought cold, nutrient-rich water from deep in oceans to the surface, moderating the sulfidic conditions. This triggered the “Ordovician radiation,” an explosion in the number of species that ultimately tripled marine biodiversity. 

For the most part, species flourished in the Ordovician, although climate fluctuations plagued certain stretches of the period.

The Ordovician period came to a chaotic end with a major mass extinction event that rocked Earth, eliminating about 85 percent of all species. Cemented as one of the “big five” mass extinctions in history, the Late Ordovician mass extinction was probably caused by glaciation and dropping sea levels, most researchers say.

Read More: How a Paleontologist Determines How Long a Mass Extinction Lasts

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