The invertebrate trace fossil Labyrintichnus in the Late Triassic red beds of the Argana Basin (Western High Atlas Mountains, Morocco). (August 2017)

• Record Type: Journal Article
• Authors: Uchman, Alfred; Lagnaoui, Abdelouahed; Saber, Hafid
• Is Part Of: Journal of African earth sciences. Volume 132(2017)
• Page Start: 127
• Page End: 138
• Publication Date: 2017-08
• Subjects: Ichnology -- Ichnotaxonomy -- Red beds -- Fluvial sediments -- Triassic -- Moroccan High Atlas -- North Africa; Earth sciences -- Africa -- Periodicals; Earth sciences -- Middle East -- Periodicals; Geology -- Africa -- Periodicals; Geology -- Middle East -- Periodicals; Sciences de la terre -- Afrique -- Périodiques; Sciences de la terre -- Moyen-Orient -- Périodiques; Géologie -- Afrique -- Périodiques; Géologie -- Moyen-Orient -- Périodiques; Earth sciences; Geology; Africa; Middle East; Periodicals; Electronic journals; 556.05
• DOI: 10.1016/j.jafrearsci.2017.04.028
• Languages: English
• ISSNs: 1464-343X

Abstract

Abstract: Labyrintichnus terrerensis Uchman and Álvaro, 2000, a cylindrical, intrastratal, passively filled trace fossil composed of irregular nets and branched galleries, so far known from Miocene marginal lacustrine clastic sediments, was found in Carnian alluvial-plain sediments of the Argana Basin, Morocco. This is the oldest occurrence of this rarely reported trace fossil. Associated tetrapod footprints and invertebrate trace fossils ( Diplopodichnus, Scoyenia, Spongeliomorpha, Taenidium, cf. Helminthoidichnites, and others) point to the Scoyenia ichnofacies typical of inundated and desiccating sediments. Co-occurring current-ripples, mudcracks and raindrop imprints confirm this interpretation. The trace fossils reflect changing consistency from softground (cf. Helminthoidichnites; Diplopodichnus ) to firm ground (e.g., Spongeliomorpha ). Beside beetles and their larvae, fly larvae are considered as possible tracemakers of shallow Labyrintichnus terrerensis on the basis of similarities to recent burrows. Graphical abstract: Highlights: Labyrintichnus terrerensis occurs in Carnian alluvial plain sediments of Morocco. This is the oldest occurrence of this rarely reported trace fossil. It occurs with vertebrate and invertebrate trace fossils of Scoyenia ichnofacies. Beside beetles and their larvae, fly larvae can be producers of Labyrintichnus.