The late Miocene marginal marine deposits of Sikkak area(Tafna Basin, northwestern Algeria) encompass moderately diversified invertebrate trace fossils preserved mainly as epichnia. The present study documents for the very first time the trace fossils occurring in this area, where16 ichnotaxa, dominated by post-depositional domichnial, repichnial and fodinichnial components, are reported: ?
Bifurculapes
isp.,
Diplocraterion
isp.,
Helminthoidichnites
isp., ?
Kouphichnium
isp., ?
Megagrapton irregulare
,
Ophiomorpha annulata, O.
cf.
nodosa
,
Oravaichnium
isp.,
Palaeophycus
isp.,
Planolites
cf.
beverleyensis
,
P. montanus
,
Ptychoplasma
isp.,
Skolithos
isp.,
S. linearis
,
Thalassinoides
isp. and
T. suevicus
. The main producers of the studied trace fossils are arthropods (crustaceans, limulids, insects), annelids (polychaetes, phoronids) and bivalves. These traces are commonly associated with sedimentary structures that are caused by hydrodynamics, suggesting high energy conditions and opportunistic colonization within a marginal marine environment (i.e., backshore to foreshore), and corresponding to the
Skolithos
ichnofacies. The crustacean trace ?
Bifurculapes
as well as the limulid trackways
Kouphichnium
are reported herein for the first time in Algeria. Sedimentological data suggest an imbricated sandstone channels within a marginal marine setting and subaerial exposures indicated by mud-cracks. Thus, the foraminiferal assemblage, dominated by shallow marine species, suggests a Tortonian age for these deposits.