PERSISTENCE OF EXTERNAL ANATOMY OF SMALL CRUSTACEANS IN A LONG TERM TAPHONOMIC EXPERIMENT

摘要

Although studied for more than a century, the preservation mechanisms of soft-bodied organisms in Lagerstatten remain disputable. One aspect of this phenomenon, the role of sediments in the decay and preservation of soft tissues, is understudied. We present the results of an 18-month decay experiment that shows the difference between the preservation of the crustacean Artemia salina buried in marine water and inside clay sediment. We found that the decay of the external tissues of A. salina is slower in the sediment than in marine water, while the internal anatomy decays rapidly in both settings. This results in the formation of exuviae-like structures, accounted for not by the recalcitrance of external tissues, but by the burying conditions in the thick marine sediment. The experiment indicates the importance of organic-mineral interactions in the understanding of the taphonomic retarding of soft-tissue decay and the persistence of fine external anatomical features.