{"id":1335,"date":"2024-02-09T23:54:00","date_gmt":"2024-02-09T22:54:00","guid":{"rendered":"https:\/\/wp.unil.ch\/paleo\/?p=1335"},"modified":"2024-09-25T11:47:01","modified_gmt":"2024-09-25T09:47:01","slug":"a-new-ordovician-polar-lagerstatte-unearthed-in-southern-france","status":"publish","type":"post","link":"https:\/\/wp.unil.ch\/paleo\/2024\/02\/a-new-ordovician-polar-lagerstatte-unearthed-in-southern-france\/","title":{"rendered":"A new Ordovician polar Lagerst\u00e4tte unearthed in southern France!"},"content":{"rendered":"\n

Today, the ANOM Lab, part of an international team led by ANOM Lab’s Farid Saleh and Bertrand Lefebvre from Lyon University, introduces a newly uncovered fossil site in the French department of H\u00e9rault, thanks to the perseverance of two dedicated amateur palaeontologists, Sylvie and \u00c9ric Monceret. The 470-million-year-old fossils, over 400 in number, unearthed by the couple at the so-called Cabri\u00e8res site, near P\u00e9zenas, are presented in an article published in Nature Ecology & Evolution.<\/em> <\/p>\n\n\n

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Artistic reconstruction of the Cabri\u00e8res Biota. <\/strong>\u00a9 Christian McCall<\/figcaption><\/figure>\n<\/div>\n\n\n

This site is particularly important because it opens a unique snapshot on ecosystems that were located the closest to the Ordovician south pole hitherto discovered. Among the most bountiful and diverse fossil beds from that geologic period, the Cabri\u00e8res site stands out for its remarkable degree of preservation, which enabled the rare discovery of soft-bodied organisms such as worms, a wide variety of algae and sponges, contributing to a better understanding of the pivotal role these highly decay-prone organisms played in ancient ecosystems.<\/p>\n\n\n\n

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Vermiform organisms from the Cabri\u00e8res Biota. <\/strong>(a) Unidentified vermiform organism UCBL-FSL713615, with possible remains of the gut and external ornamentation of tiny nodes. (b) Incomplete armoured lobopodians UCBL-FSL713616 exhibiting two sclerite plates along an elongated soft body with annulations. A lateral extension possibly represents remains of the proximal part of a lobopod. Abbreviations: an, annulations; gu, gut; ?lo, possible lobopod; otn, ornamentation of tiny nodes; sp, sclerite plates. Scale bars represent 5 mm in an and 1 mm in b.<\/strong><\/figcaption><\/figure>\n<\/div>\n\n\n
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Our findings challenge previous thinking that posited a decrease in biodiversity or even an extinction between the Cambrian and Ordovician Periods, approximately 485 million years ago. The high level of biodiversity observed does, however, confirm the hypothesis of species\u2019 migration toward the Ordovician southern hemisphere, seeking refuge from the excessive temperatures of the tropical zones. <\/p>\n\n\n\n

We also conducted a first investigation of the preservation of the fossils using X-ray fluorescence major-to-trace elemental mapping and X-ray absorption spectroscopy at the PUMA beamline of SOLEIL synchrotron on a couple specimens. We established that the fossils are essentially made up of a layer of Fe(III) oxide\/hydroxide crystals, varying in thickness and containing traces of metals. The distribution of other elements, notably manganese and arsenic, strongly suggests that iron oxide (hydr)oxides do not represent the original mode of preservation of these fossils, but rather result from more recent alteration processes, as demonstrated for other contemporary deposits. This highlights the biases that have affected the completeness of the newly discovered ecosystem, and enables finer comparisons with other fossil sites.<\/p>\n\n\n\n

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Synchrotron characterization of an assemblage of organisms from the Cabri\u00e8res Biota.<\/strong> (a) Photograph of this assemblage, consisting of two brachiopods (center), five bivalve arthropod carapaces (left and bottom right) and a trilobite head (right). (b) Distributions of manganese (red), iron (green) and potassium (blue) obtained by X-ray fluorescence mapping. (c) X-ray absorption spectroscopy reveals that iron is present in the fossils as iron oxides\/hydroxides.
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This initial study of the site inaugurates a research program that is to span several years and include large-scale excavations followed by in-depth analyses of fossils, using innovative imaging techniques. The aim is to detail the fossilized organisms\u2019 internal and external anatomies, taxonomic relationships, and modes of life.<\/p>\n\n\n\n

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Reference: Saleh F., Lustri L.,\u00a0Gueriau P., Potin G.J.-M., P\u00e9rez-Peris F., Laibl L., Jamart V., Vite A., Antcliffe J.B., Daley A.C., Nohejlov\u00e1 M., Dupichaud C., Sch\u00f6der S., B\u00e9rard E., Lynch S., Drage H.B., Vaucher R., Vidal M., Monceret E., Monceret S. & Lefebvre B. 2024.\u00a0The Cabri\u00e8res Biota (France) provides insights into Ordovician polar ecosystems.\u00a0Nature Ecology and Evolution<\/em>\u00a08, 651\u2013662. Find the article (Open Access<\/em><\/strong>) here<\/a><\/p>\n\n\n\n

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Today, the ANOM Lab, part of an international team led by ANOM Lab’s Farid Saleh and Bertrand Lefebvre from Lyon University, introduces a newly uncovered fossil site in the French department of H\u00e9rault, thanks to the perseverance of two dedicated<\/p>\n","protected":false},"author":1002590,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-1335","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-uncategorized"},"_links":{"self":[{"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/posts\/1335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/users\/1002590"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/comments?post=1335"}],"version-history":[{"count":5,"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/posts\/1335\/revisions"}],"predecessor-version":[{"id":1431,"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/posts\/1335\/revisions\/1431"}],"wp:attachment":[{"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/media?parent=1335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/categories?post=1335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.unil.ch\/paleo\/wp-json\/wp\/v2\/tags?post=1335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}