21058 - New Species Symphysurus ebbestadi n. sp. Lower Ordovician Fezouata Fm

Publication:

(1) Gutiérrez-Marco, J. C., Rábano, I., García-Bellido, D. C. 2019: "The nileid trilobite Symphysurus from upper Tremadocian strata of the Moroccan Anti-Atlas: taxonomic reappraisal and palaeoenvironmental implications" Fossils and Strata, No. 64, pp. 155-171.

The Fezouata Formation occurs in the lower part of the Lower to lower Middle Ordovician Outer Feijas Group, in the western, central and eastern Anti-Atlas
Mountains, southern Morocco (Destombes et al.1985; Gutierrez-Marco & Martin 2016).
It comes from The Konservat-Lagerstätten of Lower Fezouata Fm that spans the entire Tremadoc stage of the Ordovician system and is only present in the Moroccan Anti-Atlas. The discovery of the Fezouata biota in the latest Tremadocian of southeastern Morocco has significantly changed our understanding of the early Phanerozoic radiation. The shelly fossil record shows a well-recognized pattern of macroevolutionary stasis between the Cambrian Explosion and the Great Ordovician Biodiversification Event, but the rich soft-bodied Fezouata biota paints a different evolutionary picture. The Fezouata assemblage includes a considerable component of Cambrian holdovers alongside a surprising number of crown group taxa previously unknown to have evolved by the Early Ordovician. Study of the Fezouata biota is in its early stages, and future discoveries will continue to enrich our view of the dynamics of the early Phanerozoic radiation and of the nature of the fossil record.