First evidence of tubular fossils from the Anti-Atlas: Insights into the paleogeography of Late Ediacaran tubular fossils and the Ediacaran–Cambrian boundary in the Anti-Atlas

Abstract

The Ediacaran–Cambrian transition represents a pivotal interval in Earth’s history, marked by the emergence of tubular organisms during the Late Ediacaran and the subsequent appearance of modern animal phyla in the early Cambrian. However, such tubular organisms have never been described from the Neoproterozoic cover of the West African Craton, leaving a gap in our understanding of their exact paleogeographic distribution during this critical evolutionary period.

In this study, we describe the first occurrence of tubular fossils from the Late Ediacaran Lower unit of the Tabia Member (Taroudant Group) of the Anti-Atlas (Morocco), including Conotubus and cf. Wutubus, as well as associated oldest trace fossils (e.g., Helminthoidichnites and Gordia) and microbial structures (Ivesheadiomorphs) from shallow marine tidal flat and peritidal environments. Conotubus consists of fully pyritized, annulated tubular fossils with distinct apex–aperture differentiation. cf. Wutubus is characterized by annulated impressions with similar apex–aperture features. Notably, cf. Wutubus from the Anti-Atlas preserves a discoidal holdfast, supporting the interpretation of this taxon as a sessile organism.

The integration of these new data within both regional and global frameworks provides new insights into the Ediacaran–Cambrian boundary in the Anti-Atlas, expands the known paleogeographic distribution of Wutubus to the northern margin of Gondwana, and raises important questions regarding the biostratigraphic distribution of ichnotaxa such as Monomorphichnus and Treptichnus bifurcus.