What is a 380-million-year-old ‘squid’ doing in Leuven station?

KU Leuven

Organisation

KU Leuven

University associated with Speijer and the earlier geological guide to the station stone.

Why it matters

University associated with Speijer and the earlier geological guide to the station stone.

About

De Katholieke Universiteit Leuven of KU Leuven is een katholieke universiteit, waarvan de hoofdcampus gevestigd is in de Belgische stad Leuven. De KU Leuven biedt ook opleidingen aan op haar campussen te Brussel, Antwerpen, Gent, Kortrijk, Brugge, Geel, Diepenbeek, Sint-Katelijne-Waver en Aalst. Zij is met 22.622 personeelsleden en 65.655 studenten niet alleen de grootste Nederlandstalige universiteit, maar ook de grootste universiteit van de Lage Landen.

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Place

Leuven

Flemish city where the fossil-bearing railway station is located.

Why it matters

Flemish city where the fossil-bearing railway station is located.

About

Leuven, also called Louvain, is the capital and largest city of the province of Flemish Brabant in the Flemish Region of Belgium. A Dutch-speaking municipality, it is located about 25 kilometres east of Brussels. The municipality itself comprises the sub-municipalities of Heverlee, Kessel-Lo, Leuven proper, Wilsele, and Wijgmaal and parts of Haasrode and Korbeek-Lo. It is the eighth largest city in Belgium, with more than 100,244 inhabitants.

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The fossil matters locally because it hides in plain sight beneath commuters, students, railway employees and international visitors arriving in Leuven. De Standaard’s An Olaerts reported that the pointed shell belongs to an orthoconic cephalopod, an extinct relative of modern squid, cuttlefish and the still-living nautilus. Speijer, a professor in KU Leuven’s Department of Earth and Environmental Sciences, estimates its age at about 380 million years.

The creature lived during the Devonian period, when the geography and climate bore little resemblance to today’s Belgium. According to Speijer’s explanation, the sea in which it lived lay near the equator and existed before the modern continents assumed their present positions. Sediments and the hard remains of marine animals accumulated on the seabed, were compressed into limestone and later became part of the Ardennes

Place

Ardennes

Region identified as the source of the fossil-rich Devonian limestone.

Why it matters

Region identified as the source of the fossil-rich Devonian limestone.

About

Ardennes is a department in the Grand Est region of northeastern France named after the broader Ardennes. Its prefecture is the town Charleville-Mézières. The department has 265,893 inhabitants (2023). The inhabitants of the department are known as Ardennais or Ardennaises.

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The station floor therefore contains more than one recognisable animal. Speijer describes a crowded field of pale circles, curls and broken structures, many of them pieces of crinoids. Despite their Dutch name, zeelelies, or “sea lilies”, crinoids are animals related to starfish and sea urchins. Their soft tissue disappeared, while parts of their calcite skeletons survived as fossils.

The Geological Survey of Belgium independently documents crinoid-rich and reefal Devonian limestone around Wellin, on the southern margin of the Dinant geological basin. That research supports the broader geological setting: substantial parts of southern Belgium preserve rocks formed in warm, shallow marine environments hundreds of millions of years ago. It does not, by itself, establish the precise quarry from which the Leuven floor tile came.

A KU Leuven city-fossil guide published several years before the latest report had already highlighted an orthoconic cephalopod in the station hall. That guide described the reddish material as Ardennes reef limestone dating from roughly 375 million years ago. The university also confirms Speijer’s credentials as a professor of geology whose research includes extinction, ecosystem recovery and past climate change.

There are two useful ways of looking at the discovery. Speijer’s geological perspective treats the station floor as a slice through deep time: stone used as an ordinary building material can preserve evidence of ancient ecosystems and planetary change. The railway perspective is more immediate. A mobility guide interviewed by De Standaard initially had not noticed the fossil, illustrating how functional spaces train people to watch signs, departures and delays rather than the ground beneath them.

That contrast became especially sharp when Leuven police separately marked a subsidence in the road at the station pending repairs. Local reporting says the depression created a difference in road level, but no repair date was announced. The road defect and the fossil are unrelated: one is a present-day infrastructure problem outside the station, while the other is a natural inclusion in an old stone floor indoors. Conflating them would turn a geological curiosity into a false safety story.

The station building itself is protected heritage. The Flemish immovable-heritage inventory dates the present structure to 1876–1879 and records its later protection as a monument. The fossil-bearing floor consequently sits at the intersection of natural history, Belgian stoneworking and railway heritage, although the available sources do not establish when this particular tile was installed.

No special preservation programme or new visitor signage has been announced by NMBS, the City of Leuven or the Flemish heritage authorities. For now, the fossil remains where it has spent its railway life: enclosed in a meadow of petrified crinoid fragments while passengers hurry overhead. The next questions are whether its stone can be traced to a particular Ardennes quarry and whether Leuven or NMBS will formally identify it for travellers without obstructing a working station.