This link has a fossil photo of Clausocaris lithographica.
The fossil is 3.5 cm. long. It was found in the "plattenkalk" Main Zeta 2 of EIchstatt, Germany. This fosil dates to the Tithonian age (151 - 146 million years ago) of the Jurassic.
Clausocaris was a genus of arthropods that lived during the Triassic and Jurassic. The systematic paleontology of Clausocaris is:
Arthropoda Latreille 1829
Thylacocephala Pinna et al. 1982
Clausocarida P. Arduini 1991
Clausocaris lithographica Oppenheim 1888
C. pinnai P. Arduini 1991
Some fossil remains of the species C. pinnai were discovered in the Preone Valley in Italy. They date to the Norian age (216.5 - 203.6 million years ago) of the Triassic. [Note - The source of this information is an article by P. Arduini. It was published in 1991 Societa Italiana Scienze Naturali.]
Clausocaris is in an extinct group of marine arthropods called thylacoephalns that may have affinities to crustaceans. The carapace of thylacocephalans was large and generally laterally flattened. The compound eyes were bulbous and of considerable size. They were located in a frontal notch on the carapace. There were three pairs of large raptorial limbs. The abdomen had a set of small swimming limbs. [Note - The source of this information is and article by Jean Vannier,, Jun-Yuan Chen, Di-Ying Huang, Sylvain Charbonnier, and Xiu-Qiang Wang. It was published in 2006 in Acta Palaeontologica Polonica 51(2): 201-214. The title is The Early Cambrian origin of thylacocephalan arthropods.]