The Strawberry Bank Lagerstätte

The Strawberry Bank Lagerstätte preserves diverse species from an early Jurassic marine ecosystem in extraordinary three dimensional detail. 183 million years old, these animals lived and died at the peak of what geologists call the Toarcian Oceanic Anoxic crisis (T-OAC), a worldwide period of decreased oxygen saturation in the oceans which led to an increased rate of extinction and marked changes in the fauna of the oceans.

A juvenile Pelagosaurus crocodile, a Pachycormus fish, and an Ichthyosaur skull in three dimensions

On this page you will find an overview of the Strawberry Bank Lagerstätte, its history, and the work Bath Royal LSI has been engaged in with these astounding fossils during the 21st century.

You will also find links to further resources about Strawberry Bank and Charles Moore.

In the mid-1840s Somerset Geologist Charles Moore discovered remarkable fossil bearing strata near to his home town of Ilminster. Moore built up a substantial collection of specimens from what he called his ‘saurian, fish, and insect bed’. Since 1854 Moore’s unique collection has been preserved at Bath Royal Literary and Scientific Institution. Working with in partnership with palaeontologists from University of Bristol, Bath Royal LSI have undertaken a programme of intensive study into the site we now call the Strawberry Bank Lagerstätte.

The term lagerstätte, German in origin and literally meaning ‘storage place’, is used by palaeontologists to describe an assemblage of fossils with exceptional preservation. In the case of Strawberry Bank, the fossils were preserved rapidly within limestone concretions, before significant compaction of the sediment in which they became buried, resulting in the preservation of fine three dimensional structures and in some cases soft tissues which are usually not fossilised. Unlike many important fossil sites of Toarcian age, which preserve similar creatures but crushed flat by the weight of accruing sediments, many of the fossils at Strawberry Bank allow us to study the orientation and structure of elements within the skeleton of certain marine vertebrates, especially ichthyosaurs of two species, Pelagosaurus crocodiles, and Pachycormus fishes. Additionally, fossils from the site include a variety of invertebrates including squid and octopus like cephalopods, lobster like arthropods, and terrestrial insects of nine different orders.

On the northwest margins of the great Tethys Ocean, 183 million years ago in the Lower Jurassic, sub-tropical islands rise out of a broad shallow sea.

A lagoon on the fringes of one such island teems with life. An early summer storm has brought down several of the grand Cycad trees that form the canopy of the lush vegetation covering the island.

The branches and roots of one such tree now provide shelter for schools of small Leptolepis, fish that feed on the tiny shrimps and other invertebrates swimming in the water and burrowing in the mud.

Pachycormus, fast swimming predatory fish, often work in teams to shoal up Leptolepis before picking them off, but in summer the opportunities for an easy meal are diverse. An exhausted damselfly has become caught on the still surface of the water, and its struggles have led one Pachycormus to abandon chasing quicker prey.

Shells of the ammonite Harpoceras falciferum litter the sea floor, perhaps the first victims of hypoxia (reduced oxygen levels) that sometimes affect lagoons such as this.

 

The three ecological reconstructions above are the work of illustrator John Sibbick, commissioned by Bath Royal Literary and Scientific Institution for the exhibition Jurassic Ark, displayed at the Institution in 2014 and again updated and revised in 2021. Much of the information on the Strawberry Bank Lagerstätte pages of this website come from that exhibition. You can find more of John Sibbick’s work here.