The Cambrian Souss Lagerstätte
Geyer, Gerd & Landing, Ed. (2021). The Souss lagerstätte of the Anti-Atlas, Morocco: discovery of the first Cambrian fossil lagerstätte from Africa. Scientific Reports. 11. DOI: 10.1038/s41598-021-82546-0
Episodic low oxygenated conditions on the sea-floor are likely responsible for exceptional preservation of animal remains in the upper Amouslek Formation (lower Cambrian, Stage 3) on the northern slope of the western Anti-Atlas, Morocco. This stratigraphic interval has yielded trilobite, brachiopod, and hyolith fossils with preserved soft parts, including some of the oldest known trilobite guts. The “Souss fossil lagerstätte” (newly proposed designation) represents the first Cambrian fossil lagerstätte in Cambrian strata known from Africa and is one of the oldest trilobite-bearing fossil lagerstätten on Earth. Inter-regional correlation of the Souss fossil lagerstätte in West Gondwana suggests its development during an interval of high eustatic levels recorded by dark shales that occur in informal upper lower Cambrian Series 2 in Siberia, South China, and East Gondwana.
The Souss lagerstätte of the Anti‑Atlas, Morocco: Featuring the first Cambrian fossil Lagerstätte known from Africa.
Geyer, Gerd, Landing, Ed, Pais, Miguel Caldeira, Youbi, Nasrrddine & Boumedhi, Moulay Ahmed (2020). The Tazemmourt Section: Featuring the first Cambrian fossil Lagerstätte known from Africa. Actes de la session plénière de la Academie Hasssan II des Sciences e Techniaues du Royaume du Maroc, Année 2020. Rabat, Fevrier 2020. Pages 397-403.
The Tazemmourt section (Fig. 1) is composed of lower Cambrian strata with a total thickness of ca. 350 m. It includes rocks of the Igoudine and Amouslek formations. The section is fairly well studied (e.g., [1]–[6]), but is particularly famous for its superbly preserved trilobites (extinct marine arthropods with dorsal skeletons mineralized by calcium carbonate). These trilobites are offered for sale on the global fossil market and find their way into numerous international museum collections (e.g., [7]). Many trilobite species were described from the Tazemmourt section for the first time and have their type localities here ([1], [8]). In addition, the vertical sequence of fossils seen in the section is the basis for the biostratigraphical subdivision in the Atlas Ranges. This fossil-based zonation is part of the most important relative time subdivisions of the Cambrian Period in the West Gondwana paleocontinent and globally (e.g., [1], [6], [9]–[11]). Recent work has revealed that several horizons in the Daguinaspis Zone (based on trilobite fossils) of the Amouslek Formation yield animal remains with well preserved, internal soft-parts. These occurrences were termed the Souss Lagerstätte, and this is the first Cambrian fossil Lagerstätte known from Africa ([12], [13]). Accordingly, the Tazemmourt section certainly deserves a protected status and should be regarded as one of the key geotopes in Morocco.
