A common Muschelkalk crustacean is Pemphix, belonging to the decapoda. Exuviae and entirely preserved specimens can sometimes be found in the round living chambers at the end of Thalassinoides burrows, an evidence that this type of burrow was really made by Pemphix.
Limnic Keuper sediments can contain fossils of Triops cancriformis, a fresh water crustacean whose eggs can stand even long dry periods. After a rainfall, Triops individuals then occur in large quantities in puddles and small pools. As the tiny eggs are spread by the wind T. cancriformis may occur virtually everywhere, even in enclosed waters like playa lakes. Modern T. cancriformis can also be found in southern Germany, but only in waters that periodically totally drain. Except from an increase in size, this genus didn't undergo any further changes.
Ostracods and conchostracs are also crustaceans, although they have a reduced armour that makes them look like clams. They reach a size of only a few millimeters and preferred a brackish to slightly salinar environment. They occur in masses in respective Keuper sediments. Their chitinic armour has a high preservation potential, unlike the aragonitic shells of clams or snails. This makes them perfect index fossils in sediments that were not suitable for the preservation of other fossil remains. Due to their comparably large size and sculptured "shell", conchostracs can easily be recognized in the field, while collecting ostracods requires micropaleontogical methods.
U-shaped burrow with spreiten between two rock layers. Often has a grain-like texture due to fecal pellets. Crustaceans are believed to be the burrowers.
Upper Muschelkalk, Héming, Lorraine (F)
Exuvia
Pemphix sueuri DESMAREST
This exuvia consists of a leg and the cephalothorax. Because they periodically skin, crustaceans leave much more exuviae than real body fossils.
Upper Muschelkalk (mo3, Trigonodusdolomit), Rielingshausen
Conchostracs
Palaeestheria minuta GOLDFUSS
Lower Lettenkeuper (ku1, Anthrakonitbank), Rielingshausen