Journal of African Earth Sciences 172 (2020) 103995 Available online 29 August 2020 1464-343X/© 2020 Elsevier Ltd. All rights reserved. Late Triassic ichnoassemblage from a playa-lake system of the Coastal Meseta, Morocco: Palaeoenvironmental and palaeoecological implications Abdelkbir Hminna a, b , Abdelouahed Lagnaoui c, d, * , Tariq Zouheir a , Hafd Saber a , Joerg W. Schneider c, e a Geodynamic and Geomatic Laboratory, Department of Geology, Faculty of Sciences, Chouaïb Doukkali University, El Jadida, Morocco b Laboratory of Geosciences, Environment and Associated Resources (LGERA), Department of Geology, Sidi Mohamed Ben Abdellah University, Faculty of Sciences Dhar El Mahraz, B.P. 1796, F` es-Atlas, 30003, Morocco c Laboratory of Stratigraphy of Oil-and-Gas Bearing Reservoirs, Department of Palaeontology and Stratigraphy, Institute of Geology and Petroleum Technologies, Kazan (Volga Region) Federal University, Kazan, Russia d GCIM – Group of Consultants and Engineers of Morocco, No. 7, Rue Zemrane, Av. Mohammed VI, 10000, Rabat, Morocco e Technical University Bergakademie Freiberg, Institut für Geologie, B. V. Cotta-Str. 2, D-09596, Freiberg, Germany A R T I C L E INFO Keywords: Invertebrate trace fossils Ichnotaxonomy Scoyenia ichnofacies Carnian-rhaetian Sidi saïd maachou basin Western meseta ABSTRACT Here we present the frst comprehensive ichnotaxonomic analysis of a Late Triassic playa system from the Sidi Saïd Maachou Basin, Coastal Meseta (Western Meseta, Morocco). The Late Triassic deposits consist of sediments deposited in various nonmarine environments dominated by dry red-bed facies. These deposits yielded, so far, an ichnoassemblage consisting of the invertebrate ichnogenera Cochlichnus, Cruziana, Diplichnites, Rusophycus, Palaeophycus, and Taenidium associated with the tetrapod tracks Brachychirotherium and Rhynchosauroides. These invertebrate and vertebrate trace fossils are preserved in concave epirelief and convex hyporelief on upper and lower surfaces of laminated mudstones and fne-grained sandstones. The invertebrate ichnofossils were probably made subaqueously and indicate different behaviours of the tracemakers: walking (cursichnium, Acripes), resting (cubichnium, Rusophycus) and combined locomotion-feeding or plowing (pascichnium, Cruziana). Additionally, many other fossils are collected from the same formation, including plant impressions, rhizoliths and fsh scales. The invertebrate ichnoassemblage described herein is referred to the Scoyenia ichnofacies, which indicates opportunistic behaviours in temporarily or periodically inundated nonmarine environments, such as playa sys- tems, foodplains and lake margins. The invertebrate ichnoassemblage reported here is the frst well documented from the Sidi Saïd Maachou Basin and the Late Triassic of Morocco in general. The strata have a high potential to yield other ichnoassemblages, therefore further exploration is needed. 1. Introduction In recent years, ichnological studies of Late Palaeozoic and Early Mesozoic successions have been carried out in many parts and different stratigraphic units of Morocco: (1) Pennsylvanian deposits of the Sidi Kassem and Souss basins (Lagnaoui, 2014a, 2014b; Lagnaoui et al., 2014, 2018), (2) late Carboniferous-early Permian of Khenifra and Tiddas basins (Voigt et al., 2011a, b), (3) middle-late Permian of the Argana Basin (Voigt et al., 2009, 2010, Hminna, 2013; Hminna et al., 2012; Lagnaoui, 2014a), (4) Early-Late Triassic redbeds of the Argana Basin (Klein et al., 2009, 2010, 2011, 2018; Voigt et al., 2011b; Lag- naoui, 2014a, b; Lagnaoui et al., 2012, 2016; Zouheir et al., 2018a, b, 2019), and (5) Late Triassic strata of the Sidi Saïd Maachou Basin (Saber et al., 2007; Hminna, 2013; Hminna et al., 2008, 2009, 2013, 2017b, 2018, 2019a, b). Recently, vertebrate tracks of the ichnospecies Bra- chychirotherium parvum and B. thuringiacum were reported from the Late Triassic continental dry red beds of the Sidi Saïd Maachou basin in the Moroccan Meseta (Hminna et al., 2013, 2019a, Fig. 1). They are referred to archosaurs of the crocodile stem-group (Crurotarsi) as potential trackmakers that were widely spread over Triassic Pangaea (e.g. Lucas and Heckert, 2011; Klein et al., 2013; Hminna et al., 2019a; Lagnaoui et al., 2016; Zouheir et al., 2018a). These vertebrate tracks from the Machraa Abbass localities, described by Hminna et al. (2013), are associated with diverse invertebrate trace fossils that were collected by * Corresponding author. Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa, Instituto de Ciencias de la Tierra y Ambientales de La Pampa, Catedra de Sedimentologia, 6300, Santa Rosa, Argentina. E-mail address: abdelouahedlagnaoui@gmail.com (A. Lagnaoui). Contents lists available at ScienceDirect Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci https://doi.org/10.1016/j.jafrearsci.2020.103995 Received 4 May 2020; Received in revised form 23 August 2020; Accepted 26 August 2020