ABSTRACT
Isolated starfish- and ophiuroidossicles are quite common in clayey sediments of middle Oxfordian age, although complete specimens are very rare. This chapter describes the preservation of aste-roid-brittle star-decapod community in fine grained, silty sandstone in the southern part of the Swiss Jura mountains. The sequence of preservation is dominated by calcite cemented, fine grained, silty sandstone and consists of four different sedimentary units detected by radiography and two units interpreted to have been formerly present. After a long period of clay sedimentation, currents deposit large quantities of fine sand, which allows the brittle star-decapod community to settle. Studies on population dynamics and longetivity indicate that the life span and the sedimentation time lies between 10 and 20 years.
