Cambrian microfossils from the High Atlas, Morocco: Taxonomic, biostratigraphic, palaeobiogeographic, and depositional significance of the Brèche à Micmacca limestone beds
|Title||Cambrian microfossils from the High Atlas, Morocco: Taxonomic, biostratigraphic, palaeobiogeographic, and depositional significance of the Brèche à Micmacca limestone beds|
|Publication Type||Journal Article|
|Year of Publication||2023|
|Authors||Mghazli, K, Lazreq, N, Geyer, G, Landing, E, Boumehdi, MA, Youbi, N|
|Journal||Journal of African Earth Sciences|
Diverse helcionelloid molluscs, probable polychaetes, and sclerites of other metazoan groups are described from the Brèche à Micmacca Member at section Le IX in the Lemdad syncline in the High Atlas, southern Morocco. The collections include more than 3,000 specimens and complement earlier described faunal assemblages from this interval. The new material includes 21 species of 13 genera, with 15 helcionelloid species (or forms), one supposed orthothecid hyolith, and 5 pseudopelagielliform species. They record a relatively limited amount of biotic change through the Morocconus notabilis and Ornamentaspis frequens trilobite biozones in the Souss Basin. Eotebenna cf. papilio Runnegar and Jell1976, is the first record of the genus in Africa and West Gondwana. Dorispira? lemdadensis n. sp., Yochelcionella longituba n. sp., and Yochelcionella gracilituba n. sp. are proposed. The Le XI associations are compared with those from other localities of the Brèche à Micmacca Member in terms of their biostratigraphic and palaeoecological implications. The assemblages include forms that are similar to those from coeval faunas from the Siberian Platform, North China, Australia, and Laurentia (SNAL) and assist in interregional and continental biostratigraphic correlation and the understanding of palaeogeographic connections. This study concludes that Lower–Middle Cambrian boundary interval trilobites and small shelly fossils comprise a West Gondwanan assemblage (i.e., Morocco, Iberia, Saxo-Thuringia) that differs from palaeogeographically distant coeval faunas from tropical SNAL regions.
|Short Title||Journal of African Earth Sciences|