Fossils in Gotland

Gotland is the best place in Europe if you want to explore and experience fossils. More than 400 million years ago there was a tropical sea with very rich vegetation and wild life where Gotland now is. There were corals, cuttlefishes, trilobites and shells. Most of these species are now extinct. When the animals and plants died they became limestone formations.

Gotland was south of the equator

The sea was located somewhat south of the equator. Due to contental drift Gotland was brought to our latitudes. A part of the sea has become the limestone of Gotland. Gotlandic limestone, consisting of a 100 meter thick layer formed during 10 million years, is the best preserved in the world.

Fossiler på Gotland: Armfotingar. Den till höger är av släktet Howellella. Foto: Jim Sundberg/GotlandNature.

As much as 12 different layers can be identified in in the lime bedrock of Gotland. As the layers of Gotland are sloping, every layer can be studied somewhere on the island. In the very north-west is the Visby layer. In the very south, the Sundre layer can be seen. Every layer has its own unique composition of fossils.

Limestone of different hardness

The organisms that built and lived on the coral reefs had shells containing lime. There were both solitary and colony building individuals, such as corals, sea lilies and different types of fungi. When they died they became the hard limestone of Gotland, the reef limestone. This can, for example, be seen as a form of rauks. There are, among other places, rauk fields in Fårö, in Vamlingbo and north of Ljugarn.

Fossiler på Gotland: Raukar är exempel på revkalksten. Foto: Jim Sundberg/GotlandNature.
Rauks are an example of limestone from the reefs. Langhammars, Fårö.

The warm sea was filled with organisms, swimming around or crawling at the bottom. There were cuttlefishes, sea lilies, lamp shells, trilobites and shells. When they died, they sank into the sediment of the sea bottom. During millions of years the bottom sediment was pressed together and turned into stratified limestone. The sedimental limestone is not as hard as the limestone from the reefs. The effect of wind, waves and weather decomposes it and the fossils are revealed. The easiest way to find the fossils is searching along the stony beaches of Gotland.

Here you can see some of the fossils you may find in Gotland. Do you want to learn more? Join a guided tour – a fossil safari!

Fossiler på Gotland: fossil bläckfisk. Foto: Jim Sundberg/GotlandNature
Cuttlefish fossil

Fossils in Gotland - corals

Fossiler på Gotland: Rugos korall, arten Palaeocyclus porpita. Foto: Jim Sundberg/GotlandNature.
Fossils in Gotland: Horned corals, species Palaeocyclus porpita. Photo: Jim Sundberg/GotlandNature.
Fossiler på Gotland: kolonibildande korall av släktet Kodonophyllum. Foto: Jim Sundberg/GotlandNature.
Colony coral family Codonophyllum
Fossiler på Gotland: Tabulat korall: Kedjekorall - Halysites eller närstående släkte. Foto: Jim Sundberg/GotlandNature.
Fossils in Gotland: Tabulate coral: Halysites or related family. Photo: Jim Sundberg/GotlandNature.
Fossiler på Gotland. Rugosa koraller, så kallade tomtemössekoraller. Foto: Jim Sundberg/GotlandNature.
Solitary horn corals.
Fossiler på Gotland: Rugos korall. Möjligen släktet Tryplasma. Foto: Jim Sundberg/GotlandNature.
Solitary horn coral. Probably genus Tryplasma.
Fossiler på Gotland: Ananaskorall, Acervularia ananas.
A colony of Horn Pineapple coral, Acervularia ananas.

Fossils in Gotland - trilobites

Fossiler på Gotland: Exempel på trilobiter. Foto: Jim Sundberg/GotlandNature.
Some trilobites.
Fossiler på Gotland: En hoprullad trilobit av släktet Calymene. Foto: Jim Sundberg/GotlandNature.
A rolled up trilobite av genus Calymene.
Fossiler på Gotland: En trilobitrumpa troligen av släktet Proetus. Foto: Jim Sundberg/GotlandNature.
A trilobite. Probable genus Proetus.

Fossils in Gotland - molluscs

Fossilsafari: Exempel på olika mollusker (gastropoder). Foto: Jim Sundberg/GotlandNature.
Some fossil molluscs (gastropods).
Fossilsafari: Snäcka (mollusk) med spiralvridet skal. Foto: Jim Sundberg/GotlandNature.
Shell (mollusc) med spirally twisted shell.
Fossiler på Gotland: Snäcka, möjligen av släktet Euomphalus. Foto: Jim Sundberg/GotlandNature.
Shell, can be the genus Euomphalus.

Fossils in Gotland - lamp shells

Fossiler på Gotland: Exempel på armfotingar (brachyiopoder). Foto: Jim Sundberg/GotlandNature.
Some "lamp shells" (brachyiopods).
Fossiler på Gotland: Armfoting av släktet Howellella. Foto: Jim Sundberg/GotlandNature.
Lamp shell of the genus Howellella.
Fossiler på Gotland: Armfoting av arten Atrypa reticularis. Foto: Jim Sundberg/GotlandNature.
Fossils in Gotland: Lamp shell of the species Atrypa reticularis. Photo: Jim Sundberg/GotlandNature.

Do you want to know more about fossils in Gotland?

Fossiler på Gotland: Exempel på fingerkorall. Foto: Jim Sundberg/GotlandNature.
"Finger coral".