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El Albani A, Mazurier A, Edgecombe GD, Azizi A, El Bakhouch A, Berks HO, Bouougri EH, Chraiki I, Donoghue PCJ, Fontaine C, Gaines RR, Ghnahalla M, Meunier A, Trentesaux A, Paterson JR. Rapid volcanic ash entombment reveals the 3D anatomy of Cambrian trilobites. Science 2024; 384:1429-1435. [PMID: 38935712 DOI: 10.1126/science.adl4540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 05/23/2024] [Indexed: 06/29/2024]
Abstract
Knowledge of Cambrian animal anatomy is limited by preservational processes that result in compaction, size bias, and incompleteness. We documented pristine three-dimensional (3D) anatomy of trilobites fossilized through rapid ash burial from a pyroclastic flow entering a shallow marine environment. Cambrian ellipsocephaloid trilobites from Morocco are articulated and undistorted, revealing exquisite details of the appendages and digestive system. Previously unknown anatomy includes a soft-tissue labrum attached to the hypostome, a slit-like mouth, and distinctive cephalic feeding appendages. Our findings resolve controversy over whether the trilobite hypostome is the labrum or incorporates it and establish crown-group euarthropod homologies in trilobites. This occurrence of moldic fossils with 3D soft parts highlights volcanic ash deposits in marine settings as an underexplored source for exceptionally preserved organisms.
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Affiliation(s)
| | - Arnaud Mazurier
- University of Poitiers, UMR CNRS 7285 IC2MP, 86000 Poitiers, France
| | | | - Abdelfattah Azizi
- Laboratory of Geo-resources, Geo-environment and Civil Engineering, Department of Geosciences, Faculty of Sciences and Technics, Cadi Ayyad University, Marrakesh 40000, Morocco
| | - Asmaa El Bakhouch
- Laboratory of Geo-resources, Geo-environment and Civil Engineering, Department of Geosciences, Faculty of Sciences and Technics, Cadi Ayyad University, Marrakesh 40000, Morocco
| | - Harry O Berks
- Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - El Hafid Bouougri
- DLGR Laboratory, Department of Geology, Cadi Ayyad University, Faculty of Sciences-Semlalia, Marrakesh 40000, Morocco
| | - Ibtissam Chraiki
- DLGR Laboratory, Department of Geology, Cadi Ayyad University, Faculty of Sciences-Semlalia, Marrakesh 40000, Morocco
| | - Philip C J Donoghue
- Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Claude Fontaine
- University of Poitiers, UMR CNRS 7285 IC2MP, 86000 Poitiers, France
| | - Robert R Gaines
- Department of Geology, Pomona College, Claremont, CA 91711, USA
| | | | - Alain Meunier
- University of Poitiers, UMR CNRS 7285 IC2MP, 86000 Poitiers, France
| | - Alain Trentesaux
- University of Lille, UMR CNRS 8187 LOG, ULCO, 59655 Villeneuve d'Ascq, France
| | - John R Paterson
- Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
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Saleh F, Lustri L, Gueriau P, Potin GJM, Pérez-Peris F, Laibl L, Jamart V, Vite A, Antcliffe JB, Daley AC, Nohejlová M, Dupichaud C, Schöder S, Bérard E, Lynch S, Drage HB, Vaucher R, Vidal M, Monceret E, Monceret S, Lefebvre B. The Cabrières Biota (France) provides insights into Ordovician polar ecosystems. Nat Ecol Evol 2024; 8:651-662. [PMID: 38337049 PMCID: PMC11009115 DOI: 10.1038/s41559-024-02331-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 01/10/2024] [Indexed: 02/12/2024]
Abstract
Early Palaeozoic sites with soft-tissue preservation are predominantly found in Cambrian rocks and tend to capture past tropical and temperate ecosystems. In this study, we describe the diversity and preservation of the Cabrières Biota, a newly discovered Early Ordovician Lagerstätte from Montagne Noire, southern France. The Cabrières Biota showcases a diverse polar assemblage of both biomineralized and soft-bodied organisms predominantly preserved in iron oxides. Echinoderms are extremely scarce, while sponges and algae are abundantly represented. Non-biomineralized arthropod fragments are also preserved, along with faunal elements reminiscent of Cambrian Burgess Shale-type ecosystems, such as armoured lobopodians. The taxonomic diversity observed in the Cabrières Biota mixes Early Ordovician Lagerstätten taxa with Cambrian forms. By potentially being the closest Lagerstätte to the South Pole, the Cabrières Biota probably served as a biotic refuge amid the high-water temperatures of the Early Ordovician, and shows comparable ecological structuring to modern polar communities.
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Affiliation(s)
- Farid Saleh
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Lorenzo Lustri
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| | - Pierre Gueriau
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
- Université Paris-Saclay, CNRS, ministère de la Culture, UVSQ, MNHN, Institut photonique d'analyse non-destructive européen des matériaux anciens, Saint-Aubin, France
| | - Gaëtan J-M Potin
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| | - Francesc Pérez-Peris
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA, USA
| | - Lukáš Laibl
- Czech Academy of Sciences, Institute of Geology, Prague, Czech Republic
| | - Valentin Jamart
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| | - Antoine Vite
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
- Université de Lyon, Université Claude Bernard Lyon 1, École Normale Supérieure de Lyon, CNRS, UMR5276, LGL-TPE, Villeurbanne, France
| | | | - Allison C Daley
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| | | | - Christophe Dupichaud
- Université de Lyon, Université Claude Bernard Lyon 1, École Normale Supérieure de Lyon, CNRS, UMR5276, LGL-TPE, Villeurbanne, France
| | | | - Emilie Bérard
- Synchrotron SOLEIL, L'Orme des merisiers, Gif-sur-Yvette, France
| | - Sinéad Lynch
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| | - Harriet B Drage
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| | - Romain Vaucher
- Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| | - Muriel Vidal
- Univ Brest, CNRS, Ifremer, Geo-Ocean, UMR 6538, Plouzané, France
| | - Eric Monceret
- Société d'Etudes Scientifiques de l'Aude, Carcassonne, France
| | - Sylvie Monceret
- Société d'Etudes Scientifiques de l'Aude, Carcassonne, France
| | - Bertrand Lefebvre
- Université de Lyon, Université Claude Bernard Lyon 1, École Normale Supérieure de Lyon, CNRS, UMR5276, LGL-TPE, Villeurbanne, France
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