Trace fossils from the middle Aptian sedimentary succession of the Bellezma Mountains, NE Algeria

The Aptian sedimentary succession exposed in the southern Bellezma Mountains contains a low diversity trace fossil assemblage, with ichnofossils being common in the middle part of the studied section. The recorded trace fossils comprise eight ichnogenera: Archaeonassa, Cochlichnus, Chondrites, Gyrochorte, Palaeophycus, Protovirgularia, Rhizocorallium, and Thalassinoides. Ethologically, these ichnogenera display feeding, crawling, and dwelling activities of epi- and infaunal organisms. The presence of these trace fossils is mainly related to the activity of the deposit feeders, due to the accumulation of nutrients on the seafloor in unconsolidated, poorly sorted, soft substrate after storms under good environmental conditions. Together with sedimentological features, the ichnoassemblage suggests that the studied Aptian sedimentary succession was deposited in the upper offshore zone, corresponding to the Cruziana ichnofacies. These trace fossils are reported herein for the first time in the Bellezma Mountains. Furthermore, this study represents the first investigation of Mesozoic trace fossils in eastern Algeria.