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RESEARCH PRODUCT

A new ichnofauna from the Permian of the Zat Valley in the Marrakech High Atlas of Morocco

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Abstract A new ichnofauna from the Permian of Morocco is described in details: it is the first Palaeozoic ichnofauna from the Zat Valley in Marrakech High Atlas. The new tracksite was found in the Tighdouine region, in the middle-upper Permian of the Cham-el-Houa Siltstone Formation. An abundant and diverse ichnoassemblage composed of both protostomian (probably arthropods and annelids) traces and vertebrate tracks is recorded. The presence of protostomian burrows and traceways, associated with tetrapod tracks corresponds to the Scoyenia ichnofacies. Protostomian traces are ascribed to Diplichnites gouldi, Diplopodichnus biformis, Scoyenia cf. gracilis and Spongeliomorpha carlsbergi. Tetrapod tracks include more than 70 tracks attributed to Amphisauropus, Erpetopus, Hyloidichnus, Characichnos, and indeterminate tracks. The co-occurrence of tetrapod tracks (both walking and swimming tracks), protostomian traces, mudcracks, ripple marks, as well as the lithological features of the track-bearing levels, indicate regularly inundated depositional environments during periods of high discharge under a local seasonal climate. A sedimentological analysis shows that the depositional environments evolved from braided-meandering systems to alluvial floodplains. The track-bearing surfaces are mainly preserved in crevasse splays, levees and pond deposits. This newly discovered ichnofauna helps to better reconstruct the palaeoenvironments of the Marrakech High Atlas in Morocco during the Permian, and enlarges the palaeogeographic distribution of important ichnotaxa.