Object of the Month

Mesolimulus walchi

Jurassic

Eichstatt, Bavaria, Germany

A fine example of a horseshoe crab from the Jurassic, Solnhofen Limestone, a famous lagerstӓtten (a”fossil ore-body”) renowned for its exceptionally preserved fossil fauna. The most famous fossil from this deposit is the primitive bird, Archeopteryx.  In addition, beautifully preserved pterosaurs, insects, fish, starfish and numerous crustaceans have been found in this deposit.

Horseshoe CrabHorseshoe crabs are closely related to the extinct eurypterids (sea-scorpions), and more distantly to spiders and scorpions. This 150 million year old Mesolimulus specimen is almost identical to the modern day horseshoe crab Limulus (see picture right), found in shallow waters of South East Asia and North America.

The horseshoe crab has six pairs of legs beneath the hard, protective carapace. The first set having large claws/pincers used to catch prey, such as annelids (worms) and small molluscs, whilst the remaining five pairs are used for locomotion.