AbstractThe Upper Cretaceous “redbeds” of the lower Tremp Formation (South-Central Pyrenees, Spain) contains an ichnofauna consisting ofTaenidium barretti,Taenidium bowni,Loloichnusisp.,Arenicolitesisp.,Planolitesisp., andPalaeophycusisp. This ichnofauna occurs in deposits formed in tide-influenced meander loops and their associated overbank mudflats. Evaluation of the taphonomic controls on the Tremp ichnofauna shows that (1) two morphotypes ofTaenidium barrettiare controlled by the substrate consistence, (2)Arenicolitesmay be enlarged by erosion processes, and (3)Taenidium barrettiandPlanolitesisp. are not the same ichnotaxa showing different types of preservation. The meniscate fill inTaenidium barrettisuggests that this structure was produced by deposit feeders. The Tremp ichnofauna is grouped into two trace-fossil assemblages, a depauperate subaquatic monospecificPlanolitessuite and an assemblage representing theScoyeniaIchnofacies. Trace-fossil distribution reflects paleoenvironmental changes in the meandering channels along the stratigraphic section with thePlanolitessuite in the lowermost part of the lower interval and theScoyeniaIchnofacies in the middle and upper intervals. The lowermost suite may be likely formed seaward of the maximum salinity limit, under extreme brackish-water conditions, whereas theScoyeniaIchnofacies records a freshwater assemblage that was formed landward of the maximum salinity limit, reflecting deltaic progradation.