Unlocking the secrets of the Early Jurassic of North Africa: first record of pseudoplanktonic crinoid <i>Seirocrinus</i> (Crinoidea, Pentacrinidae) from Morocco and Algeria

Abstract

ABSTRACTThe Pliensbachian (Lower Jurassic) age-based Lower Marly Limestone Formation of the Moulay Idriss Zerhoun area (Morocco) and the Ain Ouarka Formation of the Ksour Mountains (Algeria) have yielded rare crinoids. Although crinoids have previously been described from the Jurassic of Algeria, their Pliensbachian occurrence is being reported here for the first time. On the other hand, one isocrinid taxa [Terocrinus subsulcatus (Münster in Goldfuss)] was also recorded from the Pliensbachian strata of Morocco. Additionally, now, from both Morocco and Algeria, Seirocrinus subangularis (Miller), belonging to the family Pentacrinitidae, is documented. This is a cosmopolitan and pseudoplaktonic crinoid species that is well-known from Asia, Europe, and North America. The taxonomic evaluation of the genus Seirocrinus is provided. The present records from Algeria and Morocco are the first finds of Seirocrinus from the African continent. Ticinocrinus moroccoensis sp. nov. represented by a cup of a rare cyrtocrinid (Cyrtocrinida) is associated with S. subangularis from Morocco. Globally, this is the second record of the genus; the first Ticinocrinus being described from the Pliensbachian of Switzerland. Thus, the present records from Morocco and Algeria are also the oldest cyrtocrinids from the southern margin of the Tethys.KEYWORDS: AfricaMoroccoAlgeriaJurassicechinodermscrinoids AcknowledgmentsWe thank William A. Ausich and an anonymous reviewer, and journal editors for their useful comments that improved this manuscript.Disclosure statementNo potential conflict of interest was reported by the authors.Authors’ contributionsM.A. Salamon: Conceptualization, data curation, formal analysis, funding acquisition, investigation, methodology, project administration, writing original draft, writing, review and editing; M. Benyoucef: Data curation, field works, resources, software, writing original draft; M. Benzaggagh: Field works, writing original draft, writing, review and editing; İ. Hoşgör: Methodology, writing original draft; S. Jain: Investigation, methodology, writing original draft, writing, review and editing; B.J. Płachno: Investigation, writing original draft, writing, review and editing and; O. Rahmonov: Methodology, writing original draft. All authors read and approved the final proof.Additional informationFundingThis research project is supported by the National Science Centre, Poland (www.ncn.gov.pl) – Grant No. 2020/39/B/ST10/00006.