The Fezouata Biota (Morocco) is a Burgess Shale-type (BST) assemblage that provides a wealth of information on Early Ordovician ecosystems. Much work has been done to compare the preservation of the Fezouata Biota to other BSTs. However, studies investigating preservation variations within the Fezouata Biota are rare. Here, we use probabilities to investigate the preservation of various ecological categories of Fezouata eumetazoans. Complex taphonomic processes and phylum-specific constraints have led to the better preservation of predators/scavengers in this biota. However, no differences in preservation are observed between vagile and sessile taxa. Importantly, Tremadocian taxa are better preserved than Floian ones. As such, this study highlights the gradual closure of the BST window of preservation in the Zagora region of Morocco and constitutes a benchmark for future palaeoecological and evolutionary studies on the Fezouata Biota.

Czech Academy of Sciences Institute of Geology Rozvojová 269 165 00 Prague 6 Czech Republic

Department of Natural Sciences National Museums Scotland Edinburgh EH1 1JF UK

Institute of Earth Sciences University of Lausanne Géopolis 1015 Lausanne Switzerland

Spatial Ecology and Paleontology Laboratory School of Biological Sciences Georgia Institute of Technology Atlanta GA USA

Université Claude Bernard Lyon 1 École Normale Supérieure de Lyon CNRS UMR5276 LGL‑TPE Villeurbanne France

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Vinther, J., Van Roy, P. & Briggs, D. E. Machaeridians are Palaeozoic armoured annelids. Nature451(7175), 185–188 (2008). 10.1038/nature06474 PubMed DOI

Van Roy, P. et al. Ordovician faunas of Burgess Shale type. Nature465(7295), 215–218 (2010). 10.1038/nature09038 PubMed DOI

Van Roy, P. & Briggs, D. E. A giant Ordovician anomalocaridid. Nature473(7348), 510–513 (2011). 10.1038/nature09920 PubMed DOI

Van Roy, P., Briggs, D. E. & Gaines, R. R. The Fezouata fossils of Morocco; an extraordinary record of marine life in the Early Ordovician. J. Geol. Soc.172(5), 541–549 (2015).10.1144/jgs2015-017 DOI

Van Roy, P., Daley, A. C. & Briggs, D. E. Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps. Nature522(7554), 77–80 (2015). 10.1038/nature14256 PubMed DOI

Potin, G. J. M., Gueriau, P. & Daley, A. C. Radiodont frontal appendages from the Fezouata Biota (Morocco) reveal high diversity and ecological adaptations to suspension-feeding during the Early Ordovician. Front. Ecol. Evol.11, 1214109 (2023).10.3389/fevo.2023.1214109 DOI

Potin, G. J. M. & Daley, A. C. The significance of Anomalocaris and other Radiodonta for understanding paleoecology and evolution during the Cambrian explosion. Front. Earth Sci.11, 1160285 (2023).10.3389/feart.2023.1160285 DOI

Perez-Peris, F., Laibl, L., Vidal, M. & Daley, A. Systematics, morphology, and appendages of an Early Ordovician pilekiine trilobite Anacheirurus from Fezouata Shale and the early diversification of Cheiruridae. Acta Palaeontol. Pol.66(4), 857–877 (2021).

Pérez-Peris, F. et al. A new nektaspid euarthropod from the Lower Ordovician strata of Morocco. Geol. Mag.158(3), 509–517 (2021).10.1017/S001675682000062X DOI

Laibl, L. et al. Babies from the Fezouata Biota: Early developmental trilobite stages and their adaptation to high latitudes. Geobios81, 31–50 (2023).10.1016/j.geobios.2023.06.005 DOI

Laibl, L. et al. Early developmental stages of a Lower Ordovician marrellid from Morocco suggest simple ontogenetic niche differentiation in early euarthropods. Front. Ecol. Evol.11, 1232612 (2023).10.3389/fevo.2023.1232612 DOI

Lustri, L., Gueriau, P. & Daley, A. C. Lower Ordovician synziphosurine reveals early euchelicerate diversity and evolution. Nat. Commun.15(1), 3808 (2024). 10.1038/s41467-024-48013-w PubMed DOI PMC

Lustri, L. et al. New perspectives on the evolutionary history of xiphosuran development through comparison with other fossil euchelicerates. Front. Ecol. Evol.11, 1270429 (2023).10.3389/fevo.2023.1270429 DOI

Drage, H. B., Legg, D. A. & Daley, A. C. Novel marrellomorph moulting behaviour preserved in the Lower Ordovician Fezouata Shale, Morocco. Front. Ecol. Evol.11, 1226924 (2023).10.3389/fevo.2023.1226924 DOI

Saleh, F. et al. Large trilobites in a stress-free Early Ordovician environment. Geol. Mag.158(2), 261–270 (2021).10.1017/S0016756820000448 DOI

Martin, E. L. et al. Biostratigraphic and palaeoenvironmental controls on the trilobite associations from the Lower Ordovician Fezouata Shale of the central Anti-Atlas, Morocco. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 142–154 (2016).10.1016/j.palaeo.2016.06.003 DOI

Ortega-Hernández, J., Van Roy, P. & Lerosey-Aubril, R. A new aglaspidid euarthropod with a six-segmented trunk from the Lower Ordovician Fezouata Konservat-Lagerstätte, Morocco. Geol. Mag.153(3), 524–536 (2016).10.1017/S0016756815000710 DOI

Gutiérrez-Marco, J. C., García-Bellido, D. C., Rábano, I. & Sá, A. A. Digestive and appendicular soft-parts, with behavioural implications, in a large Ordovician trilobite from the Fezouata Lagerstätte, Morocco. Sci. Rep.7(1), 39728 (2017). 10.1038/srep39728 PubMed DOI PMC

Saleh, F., Daley, A. C., Lefebvre, B. & El Hariri, K. Insights on the rise of animal life from Cambrian and Ordovician Lagerstätten. Front. Earth Sci.11, 1343862 (2023).10.3389/feart.2023.1343862 DOI

Saleh, F. et al. Storm-induced community dynamics in the Fezouata Biota (Lower Ordovician, Morocco). Palaios33(12), 535–541 (2018).10.2110/palo.2018.055 DOI

Sumrall, C. D. & Zamora, S. Ordovician edrioasteroids from Morocco: Faunal exchanges across the Rheic Ocean. J. Syst. Palaeontol.9(3), 425–454 (2011).10.1080/14772019.2010.499137 DOI

Lefebvre, B. et al. Palaeoecological aspects of the diversification of echinoderms in the Lower Ordovician of central Anti-Atlas, Morocco. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 97–121 (2016).10.1016/j.palaeo.2016.02.039 DOI

Lefebvre, B. et al. Exceptionally preserved soft parts in fossils from the Lower Ordovician of Morocco clarify stylophoran affinities within basal deuterostomes. Geobios52, 27–36 (2019).10.1016/j.geobios.2018.11.001 DOI

Allaire, N. et al. Morphological disparity analysis and systematic revision of the eocrinoid genus Rhopalocystis (Echinodermata, Blastozoa) from the Lower Ordovician of the central Anti-Atlas (Morocco). J. Paleontol.91, 685–714 (2017).10.1017/jpa.2017.6 DOI

Saleh, F., Lefebvre, B., Hunter, A. W. & Nohejlová, M. Fossil weathering and preparation mimic soft tissues in eocrinoid and somasteroid echinoderms from the Lower Ordovician of Morocco. Microsc. Today28(1), 24–28 (2020).10.1017/S1551929519001238 DOI

Dupichaud, C. et al. Solutan echinoderms from the Fezouata Shale Lagerstätte (Lower Ordovician, Morocco): Diversity, exceptional preservation, and palaeoecological implications. Front. Ecol. Evol.11, 1290063 (2023).10.3389/fevo.2023.1290063 DOI

Hunter, A. W. & Ortega-Hernández, J. A new somasteroid from the Fezouata Lagerstätte in Morocco and the Early Ordovician origin of Asterozoa. Biol. Lett.17(1), 20200809 (2021). 10.1098/rsbl.2020.0809 PubMed DOI PMC

Blake, D. B. & Hotchkiss, F. H. Origin of the subphylum Asterozoa and redescription of a Moroccan Ordovician somasteroid. Geobios72, 22–36 (2022).10.1016/j.geobios.2022.07.002 DOI

Gutiérrez-Marco, J. C. & Martin, E. L. Biostratigraphy and palaeoecology of Lower Ordovician graptolites from the Fezouata Shale (Moroccan Anti-Atlas). Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 35–49 (2016).10.1016/j.palaeo.2016.07.026 DOI

Nanglu, K., Waskom, M. E., Richards, J. C. & Ortega-Hernández, J. Rhabdopleurid epibionts from the Ordovician Fezouata Shale biota and the longevity of cross-phylum interactions. Commun. Biol.6(1), 1002 (2023). 10.1038/s42003-023-05377-x PubMed DOI PMC

Marek, L. The Ordovician Hyolitha of Anti-Atlas (Morocco). Sborník Národního muzea v Praze Řada B, Přírodní vědy39, 1–36 (1983).

Mus, M. M. A hyolithid with preserved soft parts from the Ordovician Fezouata Konservat-Lagerstätte of Morocco. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 122–129 (2016).10.1016/j.palaeo.2016.04.048 DOI

Kröger, B. & Lefebvre, B. Palaeogeography and palaeoecology of early Floian (Early Ordovician) cephalopods from the Upper Fezouata Formation, Anti-Atlas, Morocco. Foss Rec.15(2), 61–75 (2012).10.1002/mmng.201200004 DOI

Polechová, M. The bivalve fauna from the Fezouata Formation (Lower Ordovician) of Morocco and its significance for palaeobiogeography, palaeoecology and early diversification of bivalves. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 155–169 (2016).10.1016/j.palaeo.2015.12.016 DOI

Ebbestad, J. O. R. & Lefebvre, B. An unusual onychochilid mollusc from the Ordovician (Tremadocian) Fezouata formation, Morocco. Geobios48(6), 427–438 (2015).10.1016/j.geobios.2015.09.004 DOI

Ebbestad, J. O. R. Gastropoda, Tergomya and Paragastropoda (Mollusca) from the Lower Ordovician Fezouata Formation, Morocco. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 87–96 (2016).10.1016/j.palaeo.2016.01.003 DOI

Vinther, J., Parry, L., Briggs, D. E. & Van Roy, P. Ancestral morphology of crown-group molluscs revealed by a new Ordovician stem aculiferan. Nature542(7642), 471–474 (2017). 10.1038/nature21055 PubMed DOI

Nanglu, K. & Ortega-Hernández, J. Post-Cambrian survival of the tubicolous scalidophoran Selkirkia. Biol. Lett.20(3), 20240042 (2024). 10.1098/rsbl.2024.0042 PubMed DOI PMC

Saleh, F. et al. Insights into soft-part preservation from the Early Ordovician Fezouata Biota. Earth-Sci. Rev.213, 103464 (2021).10.1016/j.earscirev.2020.103464 DOI

Richards, J. C., Nanglu, K. & Ortega-Hernández, J. The Fezouata Shale Formation biota is typical for the high latitudes of the Early Ordovician: a quantitative approach. Paleobiology50, 226–238 (2024).10.1017/pab.2024.7 DOI

Botting, J. P. Diversity and ecology of sponges in the Early Ordovician Fezouata Biota, Morocco. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 75–86 (2016).10.1016/j.palaeo.2016.05.018 DOI

Van Iten, H. et al. Palaeobiogeography, palaeoecology and evolution of Lower Ordovician conulariids and Sphenothallus (Medusozoa, Cnidaria), with emphasis on the Fezouata Shale of southeastern Morocco. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 170–178 (2016).10.1016/j.palaeo.2016.03.008 DOI

Martin, E. L., Lerosey-Aubril, R. & Vannier, J. Palaeoscolecid worms from the Lower Ordovician Fezouata Lagerstätte, Morocco: Palaeoecological and palaeogeographical implications. Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 130–141 (2016).10.1016/j.palaeo.2016.04.009 DOI

Saleh, F. et al. Contrasting Early Ordovician assembly patterns highlight the complex initial stages of the Ordovician Radiation. Sci. Rep.12(1), 3852 (2022). 10.1038/s41598-022-07822-z PubMed DOI PMC

Saleh, F., Antcliffe, J. B., Lustri, L., Daley, A. C. & Gibert, C. Cambrian and Ordovician diversity fluctuations could be resolved through a single ecological hypothesis. Lethaia56(3), 1–13 (2023).10.18261/let.56.3.7 DOI

Martin, E. L. et al. The Lower Ordovician Fezouata Konservat-Lagerstätte from Morocco: Age, environment and evolutionary perspectives. Gondwana Res.34, 274–283 (2016).10.1016/j.gr.2015.03.009 DOI

Lefebvre, B. et al. Age calibration of the Lower Ordovician Fezouata Lagerstätte, Morocco. Lethaia51(2), 296–311 (2018).10.1111/let.12240 DOI

Saleh, F., Pittet, B., Perrillat, J. P. & Lefebvre, B. Orbital control on exceptional fossil preservation. Geology47(2), 103–106 (2019).10.1130/G45598.1 DOI

Saleh, F. et al. New fossil assemblages from the Early Ordovician Fezouata biota. Sci. Rep.12(1), 20773 (2022). 10.1038/s41598-022-25000-z PubMed DOI PMC

Vaucher, R., Martin, E. L., Hormière, H. & Pittet, B. A genetic link between Konzentrat-and Konservat-Lagerstätten in the Fezouata Shale (lower Ordovician, Morocco). Palaeogeogr. Palaeoclimatol. Palaeoecol.460, 24–34 (2016).10.1016/j.palaeo.2016.05.020 DOI

Vaucher, R., Pittet, B., Hormière, H., Martin, E. L. & Lefebvre, B. A wave-dominated, tide-modulated model for the Lower Ordovician of the Anti-Atlas, Morocco. Sedimentology64(3), 777–807 (2017).10.1111/sed.12327 DOI

Saleh, F. et al. Taphonomic pathway of exceptionally preserved fossils in the Lower Ordovician of Morocco. Geobios60, 99–115 (2020).10.1016/j.geobios.2020.04.001 DOI

Saleh, F., Daley, A. C., Lefebvre, B., Pittet, B. & Perrillat, J. P. Biogenic iron preserves structures during fossilization: A hypothesis: iron from decaying tissues may stabilize their morphology in the fossil record. BioEssays42(6), 1900243 (2020).10.1002/bies.201900243 PubMed DOI

Saleh, F. et al. Iron from continental weathering dictated soft-part preservation during the Early Ordovician. Terra Nova34(3), 163–168 (2022).10.1111/ter.12572 DOI

Gueriau, P., Saleh, F., Laibl, L., Peris, F.P., Lustri, L., Mocuta, C., Réguer, S., Cohen, S. X., Bertrand, L. & Daley, A. C. Trace elements discriminate between tissues in highly weathered fossils (2023).

Saleh, F. et al. Taphonomic bias in exceptionally preserved biotas. Earth Planet. Sci. Lett.529, 115873 (2020).10.1016/j.epsl.2019.115873 DOI

Saleh, F. et al. A novel tool to untangle the ecology and fossil preservation knot in exceptionally preserved biotas. Earth Planet. Sci. Lett.569, 117061 (2021).10.1016/j.epsl.2021.117061 DOI

Saleh, F. et al. Probability-based preservational variations within the early Cambrian Chengjiang biota (China). PeerJ10, e13869 (2022). 10.7717/peerj.13869 PubMed DOI PMC

Saleh, F., Clements, T., Perrier, V., Daley, A. C. & Antcliffe, J. B. Variations in preservation of exceptional fossils within concretions. Swiss J. Palaeontol.142(1), 20 (2023). 10.1186/s13358-023-00284-4 PubMed DOI PMC

Whitaker, A. F., Schiffbauer, J. D., Briggs, D. E., Leibach, W. W. & Kimmig, J. Preservation and diagenesis of soft-bodied fossils and the occurrence of phosphate-associated rare earth elements in the Cambrian (Wuliuan) Spence Shale Lagerstätte. Palaeogeogr. Palaeoclimatol. Palaeoecol.592, 110909 (2022).10.1016/j.palaeo.2022.110909 DOI

Saleh, F. et al. Skeletal elements controlled soft-tissue preservation in echinoderms from the Early Ordovician Fezouata Biota. Geobios81, 51–66 (2023).10.1016/j.geobios.2023.08.001 DOI

Saleh, F. et al. The Cabrières Biota (France) provides insights into Ordovician polar ecosystems. Nat. Ecol. Evol.8, 651–662 (2024). 10.1038/s41559-024-02331-w PubMed DOI PMC

Botting, J. P. et al. A Middle Ordovician Burgess Shale-type fauna from Castle Bank, Wales (UK). Nat. Ecol. Evol.7(5), 666–674 (2023). 10.1038/s41559-023-02038-4 PubMed DOI

Hearing, T. W. et al. Survival of Burgess Shale-type animals in a Middle Ordovician deep-water setting. J. Geol. Soc.173(4), 628–633 (2016).10.1144/jgs2015-131 DOI