Ethologic and ontogenic significance of the Pliocene trace fossil Sinusichnus sinuosus from the northwestern Mediterranean

The trace fossil Sinusichnus sinuosus Gibert 1996 is described and interpre ted as an open burrow system, attributed to a crustacean tracemaker, that s hares some features with fodinichnial networks, such as Thalassinoides and Ophiomorpha, and with graphoglyptid burrows, such as Protopaleodictyon and Cosmorhaphe. These similarities suggest that Sinusichnus could have been pr oduced by an animal combining deposit-feeding and farming (or trapping) str ategies. The Sinusichnus record has yielded juvenile and adult burrows, oft en in close association. On account of minor morphologic differences betwee n the two, juvenile tracemakers could have employed an agrichnial feeding s trategy, whereas adults could have employed fodinichnial feeding.