Katie, Assistant Curator. Lapworth Museum of Geology, talks about her choice of the Object of the Month
Video transcript here
Solnhofen Limestone, Upper Jurassic
This exceptionally preserved fossil shrimp is fully articulated complete with appendages including legs and antennae, body parts which are not normally preserved.
The specimen is from the Solnhofen Limestone in Germany, which is a world famous lagerstätten, meaning a site containing an exceptionally preserved fossil fauna. Deposited during the Late Jurassic approximately 150 million years ago, this shrimp would have lived in warm shallow sea conditions. It had a benthic mode of life, living near the sea floor within shallow waters and would have used its numerous legs to swim. During the larval stage it would have fed on plankton and when larger would have preyed on small marine organisms, it would in turn have been preyed on itself by fish and marine reptiles.
To produce such a specimen complete with appendages, the conditions in which it is preserved have to be just right. The limestone was deposited in a lagoon environment associated with a warm shallow sea. High evaporation rates would have led to increased salinity levels and with the anoxic bottom waters conditions would have been inhospitable for most living creatures. Organisms were probably washed into the lagoon during storm events, and then quickly died within the hostile environment before being buried by sediment.
The harsh environmental conditions within the lagoon combined with rapid burial, prevented scavengers or bacteria from breaking down the remains and allowed the shrimp to be preserved in such fine detail.