Synthèse sur la flore des nodules du Lagerstätte de Montceau-les-Mines (Carbonifère supérieur,France)

The flora from the Montceau-les-Mines Lagerstätte (Late Pennsylvanian, Stephanian, France) is preserved in small sideritic nodules and was studied in three locations in the (1) Saint-Louis, (2) Saint-François, and (3) Sainte-Hélène opencast mines. Qualitative and quantitative analyses of plant diversity and floristic composition in about 7000 nodules indicate substantial variations in the floral composition of these opencast mines. More than 50 taxa are recognized and belong to groups typical of the Late Carboniferous flora (lycopsids, sphenopsids, tree ferns, and pteridosperms). Arborescent sphenopsids and tree ferns were the major components at Saint-Louis, whereas the flora from Saint-François consisted mainly of pteridosperms; the one from Sainte-Hélène has a more balanced composition. Taphonomic and sedimentological data show that the flora contained in the nodules was hypoautochthonous to parautochthonous. The Montceau Basin displayed a mosaic of paleoenvironments (e.g., deltaic lacustrine, paludal to fluvial) which favored colonization by plants and animals.     

The presumed hagfish Myxineidus gononorum from the Upper Carboniferous of Montceau-les-Mines (Saône-et-Loire,France): New data obtained by means of Propagation Phase Contrast X-ray Synchrotron Microtomography

The re-examination of the presumed hagfish Myxineidus gononorum from the Carboniferous of Montceau-les-Mines by means of propagation phase contrast X-ray synchrotron microtomography confirms the presence of two series of non-mineralized denticles arranged in chevrons in the oral region. It also indicates the presence of possible traces of post-mortem mineralized soft tissues. A peculiar zone of less X ray-absorbing matter around the animal suggests the presence of an enlarged, lamprey-like oral disc. Re-interpreting Myxineidus as a lamprey would be in better agreement with the reputedly fresh-water environment of the Montceau-les-Mines Lagerstätte.     

Le bassin de l’homme du Pléistocène supérieur de Liujiang, Sud de la Chine : taille du corps, forme du corps et encéphalisation

The Late Pleistocene hominin fossil assemblage from Liujiang, South China include a fairly well-preserved cranium, a right os coxa, a complete sacrum, and other postcranial elements all belonging to a single individual. This rare discovery offers us a unique and singular opportunity in understanding this Late Pleistocene hominin's body proportion and relative cranial capacity (encephalization quotient [EQ]), and also pelvic morphology. Using the available right innominate and its mirror-imaged left side, we reconstruct Liujiang hominin's pelvis. Our analysis of the pelvis indicates that the Liujiang hominin has a very gracile and modern-like pelvic morphology. Indeed, all of the pelvic dimensions are smaller than those of other Pleistocene hominins. Moreover, the pelvic characteristics typical of Middle and Late Pleistocene hominins including Neanderthals cannot be identified in the Liujiang pelvis. In contrast, both Liujiang's metric and non-metric features indicate affinities to more recent human populations including our modern Chinese collections from Guangxi of south China. Further support of this assessment comes from the EQ value of 5.754 for Liujiang which is closer to Minatogawa 2 and modern Chinese populations than to Middle and Late Pleistocene fossil hominins. Our analysis of body shape shows that Liujiang has body proportion (i.e. body height relative to body breadth) typical of warm-adapted populations. Based on these findings, we reason that the modern physical characteristics of Liujiang may allude to a more recent geological age. Alternatively, its morphological “modernity” could also point to a much higher degree of skeletal variation within Late Pleistocene hominins in East Asia.     

Tomographic Reconstruction of Neopterous Carboniferous Insect Nymphs

Two new polyneopteran insect nymphs from the Montceau-les-Mines Lagerstätte of France are presented. Both are preserved in three dimensions, and are imaged with the aid of X-ray micro-tomography, allowing their morphology to be recovered in unprecedented detail. One–Anebos phrixos gen. et sp. nov.–is of uncertain affinities, and preserves portions of the antennae and eyes, coupled with a heavily spined habitus. The other is a roachoid with long antennae and chewing mouthparts very similar in form to the most generalized mandibulate mouthparts of extant orthopteroid insects. Computer reconstructions reveal limbs in both specimens, allowing identification of the segments and annulation in the tarsus, while poorly developed thoracic wing pads suggest both are young instars. This work describes the morphologically best-known Palaeozoic insect nymphs, allowing a better understanding of the juveniles’ palaeobiology and palaeoecology. We also consider the validity of evidence from Palaeozoic juvenile insects in wing origin theories. The study of juvenile Palaeozoic insects is currently a neglected field, yet these fossils provide direct evidence on the evolution of insect development. It is hoped this study will stimulate a renewed interest in such work.     

A Silurian myodocope with preserved soft-parts: cautioning the interpretation of the shell-based ostracod record

Ostracod crustaceans are the most abundant fossil arthropods. The Silurian Pauline avibella gen. et sp. nov., from the Herefordshire Lagerstätte, UK, is an extremely rare Palaeozoic example with soft-part preservation. Based on its soft-part morphology, especially the exceptionally preserved limbs and presence of lateral eyes, it is assigned to the myodocopid myodocopes. The ostracod is very large, with an epipod on the fifth limb pair, as well as gills implying the presence of a heart and an integrated respiratory–circulatory system as in living cylindroleberidid myodocopids. Features of its shell morphology, however, recall halocyprid myodocopes and palaeocopes, encouraging caution in classifying ostracods based on the carapace alone and querying the interpretation of their shell-based fossil record, especially for the Palaeozoic, where some 500 genera are presently assigned to the Palaeocopida.     

Sur un bois fossile du mésozoïque de la colombie: Protophyllocladoxylon rosablancaense n. sp.

The fossil wood studied in this report, was collected in the Middle Valley of Río Magdalena (Colombia) by Professor J. de Porta. It is of a homoxylous structure of the araucarian type: Protophyllocladoxylon rosablancaense n. sp. The wood stems from the Rosa Blanca Formation (Lower Cretaceous, Hauterivian?). A comparative study of fossil woods of the genera ProtocircoporoxylonVogellehner and ProtophyllocladoxylonKräusel is made.     

Les nodules fossilifères de la découverte Saint-Louis à Montceau-les-Mines

The collect of the fossiliferous nodules starts in 1979 in the Saint-Louis opencast mine at Montceau-les-Mines, France. A team of amateur paleontologists excavates more than 100,000 nodules containing very well-preserved fauna and flora from the Late Carboniferous (Stephanian).     

A New Three-Dimensionally Preserved Xiphosuran Chelicerate from the Montceau-Les-Mines Lagerstätte (Carboniferous, France)

Excellent three dimensional preservation of 142 specimens of Alanops magnificus gen. et sp. nov. (Chelicerata: Xiphosura) from the Stephanian Konservat-Lagerstätte of Montceau-les-Mines (Saône-et-Loire, France), exposes the carapace design and hitherto unrecorded details of fossil xiphosuran ventral anatomy, and makes possible an interpretation of appendicular functional morphology. All legs are long, slender and chelate. The chelate condition of the fifth leg and the shape of the prosoma (highly vaulted with a subvertical frontal area) indicate that the animal was neither a burrower like Recent xiphosurans (e.g. Limulus ) nor an active swimmer as suggested for other extinct forms, but was more likely to have been a benthic crawler. The ability to fold up is attested by both partly enrolled specimens showing appendages withdrawn into the prosomal cavity, and by coaptive devices on the external and internal margins of both prosoma and opisthosoma. The low-level articulation system at the boundary between the two shields allowed both the carapace closure and the complete outstretching of the animal. The unusually small adult size of Alanops magnificus gen. et sp. nov. combined with the loss of ophthalmic ridges and spines is interpreted as indicating a paedomorphic derivation from a bellinurine stock. The depositional environment (limnic intramontane basin) and faunal association (dominated by syncarids and bivalves) of Alanops indicate that the animal probably lived in fresh water.     

Charophytes, indicateurs de paléobathymétrie du lac Tigalmamine (Moyen Atlas, Maroc)

A paleolimnological study can be particularly accurate in situations where the species found in the sediments have persisted in the same lake and can provide a direct modern analogue for interpretation. Lake Tigalmamine, thus, represents an exceptionally favourable context, compared to most paleolakes in North Africa, as this site allows comparing the fossil remains of the Characeae to those produced by the living plants. Tigalmamine is a hydrosystem composed of three karstic lakes located at 1626 m above sea level in the Middle Atlas of Morocco. The site had been the subject of a 16 m long core taken in the center of the central lake under 16 m of water (core C 86 in Lamb and Kaars, 1995 [The Holocene 5 (1995) 400-408]). The section represents the total of the Holocene from 10,200 BP to Present (El Hamouti et al., 1991 [Comptes Rendus de l’Académie des Sciences de Paris 2 (1991) 259-265]; Lamb et al., 1995 [Nature 373 (1995) 134-137]). The latter published a synthesis of the pluridisciplinary studies conducted on this core. Also, the numerous gyrogonites isolated from that core had been determined as Chara hispida (Soulié-Märsche in Benkaddour, 1993 [Changements hydrologiques et climatiques dans le Moyen-Atlas marocain : chronologie, minéralogie, géochimie isotopique et élémentaire des sédiments lacustres de Tigalmamine. PhD thesis, Université Paris-Sud, Orsay (inédit)]). Further fieldwork at Tigalmamine by the authors of the present paper in year 2000 showed that Chara hispida is still present in the lake where it forms a belt of submerged vegetation restricted to the range of 2 to 9 m water depth. This paper describes the morphological and ecological characteristics of the extant Chara hispida as a reference for the interpretation of the fossil remains. Based on these data, the frequency changes of the gyrogonites in the core sediments become significant in terms of bathymetry. The detailed analysis of the charophytes from the core, as a complement to the previous studies, confirms the existence of four Holocene phases with lake level low stand at Tigalmamine. The aim of the present study is to enhance the value of the charophytes as a useful complementary tool for paleolimnological reconstruction.     

Historique de la découverte et des recherches sur la calotte crânienne d’Homo erectus archaïque de Kocabaş, Bassin de Denizli,Anatolie, Turquie

In November 2002, during the study of the Plio-Pleistocene formations of Denizli Basin, containing significant active and fossil travertine deposits, during a visit to the Dalmersan factory, near the Kocaba? quarries, I identified a Hominid skullcap among bones retrieved during the cutting of travertine slabs. I immediately attributed this skullcap to a Homo erectus. I then handed over the study of this fossil, first to Professor John Kappelman from Texas University, then to a multidisciplinary study led by the Human Paleontology Institute in Paris.     

Ein Beitrag zur Kenntnis der Alttertiärflora des Harzvorlandes

Zusammenfassung In den alttertiären Schichten über der mitteleozänen Braunkohle des Harzvorlandes fanden sich früher und während der letzten Jahre Reste von Früchten und Samen. Der größte Teil der Fossilien geht auf die Steinkerne von Mastixioideen zurück. Diese Cornaceenunterfamilie ist aus dem Eozän Englands bekannt und in den mittel- bis oberoligozänen Braunkohlenschichten Deutschlands durch zahllose Reste mehrerer Formen vertreten. Das Alter der Funde aus dem Harzvorland kann gegenwärtig nicht mit Sicherheit bestimmt werden. Jedoch ist anzunehmen, daß sie vorwiegend aus der mitteleozänen Braunkohle stammen und sich auf sekundärer Lagerstätte in Schichten des älteren Oligozäns befinden. Neben Begleitformen aus den Familien der Taxodiaceen, Juglandaceen, Myricaceen und Symplocaceen werden besonders eingehend Mastixioideenreste beschrieben. Die Ergebnisse können zeigen, daß tertiäre Fruchtfossilien oft noch sehr gut erhalten und auf Grund einer genauen Analyse sicher zu bestimmen sind.Mit 17 Textabbildungen (71 Einzelbildern).     

The Montceau-les-Mines Lagerstätte (Late Carboniferous,France)

The Montceau-les-Mines Lagerstätte (Late Stephanian, Late Carboniferous) is located northeast of the French Massif Central. Situated at equatorial latitudes during the Pennsylvanian, this Lagerstätte, probably a freshwater environment, preserves a rich and diverse flora (lycopsids, sphenopsids, ferns, pteridosperms, and cordaites) and fauna (bivalves, annelids, crustaceans, myriapods, insects, chelicerates, myxinoids, actinopterygians, sarcopterygians and tetrapods). These exceptionally preserved fossils can be found either flattened in shales or three-dimensionally preserved in sideritic nodules. The fossils from the nodules are exceptional for at least two reasons: the absence of major disarticulation of their body structure and the preservation of soft parts and extremely fragile cuticular structures. Such preservation was made possible by the combination of several factors: rapid burial in fine anoxic mud, early siderite precipitation (inducing the nodule formation) and phosphatization of cuticles and soft-bodied features.     

Architecture and function of the lophophore in the problematic brachiopod Heliomedusa orienta (Early Cambrian, South China)

The detailed structure of the lophophore is a key diagnostic character in the definition of higher brachiopod taxa. The problematic Heliomedusa orienta Sun and Hou, from the Lower Cambrian Chengjiang Lagerstätte of Yunnan, southwestern China, has a well-preserved lophophore, which is unlike that of any known extant or extinct brachiopods. Based on a comparative study of lophophore disposition in H. orienta and the extant discinid Pelagodiscus atlanticus, the in- and excurrent pattern and shell orientation of H. orienta are described and discussed. Reconstructions of lophophore shape and function are based on numerous specimens and comparison with P. atlanticus. The lophophore is composed of a pair of lophophoral arms that freely arch posteriorly rather than coiling anteriorly as commonly seen in fossil and recent lingulids. The lophophore is attached to the dorsal lobe of the mantle; it has neither calcareous nor chitinous supporting structures, and is disposed symmetrically on either side of the valve midline. The mouth can be inferred to be located at the base of the two brachial tubes, slightly posterior to the anterodorsal projection of the body wall. The lophophoral arms bear laterofrontal tentacles with a double row of cilia along their lateral edge, as in extant lingulid brachiopods. The main brachial axes are also ciliated, which presumably facilitated transport of mucous-bound nutrient particles to the mouth. The unique organization of the lophophore in Heliomedusa is not like any known fossil and living brachiopods. This clearly demonstrates that H. orienta is not a member of any crown group. It is here considered as a member of the brachiopod stem group, which challenges recent interpretations of a close discinid affinity.     

A soft-bodied lophophorate from the Silurian of England

Soft-bodied taxa comprise an important component of the extant lophophorate fauna, but convincing fossils of soft-bodied lophophorates are extremely rare. A small fossil lophophorate, attached to a brachiopod dorsal valve, is described from the Silurian (Wenlock Series) Herefordshire Lagerstätte of England. This unmineralized organism was bilaterally symmetrical and comprised a subconical body attached basally to the host and partially enclosed by a broad ‘hood’; the body bore a small, coiled lophophore. Where the hood attached laterally, there is a series of transverse ridges and furrows. The affinities of this organism probably lie with Brachiopoda; the hood is interpreted as the homologue of a dorsal valve/mantle lobe, and the attachment as the homologue of the ventral valve and/or pedicle. The ridges are arranged in a manner that suggests constructional serial repetition, indicating that they are unlikely to represent mantle canals. Extant brachiopods are not serially structured, but morphological and molecular evidence suggests that their ancestors were. The new organism may belong to the brachiopod stem group, and might also represent a significant element of the Palaeozoic lophophorate fauna.     

Almost a spider: a 305-million-year-old fossil arachnid and spider origins

Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasieri gen. et sp. nov. from the Late Carboniferous (Stephanian, ca 305–299 Ma) of Montceau-les-Mines, France. It is three-dimensionally preserved within a siderite concretion, allowing both laboratory- and synchrotron-based phase-contrast computed tomography reconstruction. The latter is a first for siderite-hosted fossils and has allowed us to investigate fine anatomical details. Although distinctly spider-like in habitus, this remarkable fossil lacks a key diagnostic character of Araneae: spinnerets on the underside of the opisthosoma. It also lacks a flagelliform telson found in the recently recognized, spider-related, Devonian–Permian Uraraneida. Cladistic analysis resolves our new fossil as sister group to the spiders: the spider stem-group comprises the uraraneids and I. brasieri. While we are unable to demonstrate the presence of spigots in this fossil, the recovered phylogeny suggests the earliest character to evolve on the spider stem-group is the secretion of silk. This would have been followed by the loss of a flagelliform telson, and then the ability to spin silk using spinnerets. This last innovation defines the true spiders, significantly post-dates the origins of silk, and may be a key to the group''s success. The Montceau-les-Mines locality has previously yielded a mesothele spider (with spinnerets). Evidently, Late Palaeozoic spiders lived alongside Palaeozoic arachnid grades which approached the spider condition, but did not express the full suite of crown-group autapomorphies.     

Epibionts on the lingulate brachiopod Diandongia from the Early Cambrian Chengjiang Lagerst?tte,South China

The classic Chengjiang Lagerstätte (Lower Cambrian, Atdabanian stage: Yu''anshan Formation) Yunnan, southwestern China, has yielded, besides the exceptional and often controversial soft-bodied fossils, a fauna of primitive/early lingulid brachiopods. Diandongia pista (Rong 1974) is one of the commonest and most strongly mineralized of the phosphatic brachiopods from the Lagerstätte. The shells of this species have been found to commonly serve as a basibiont host. Epibionts comprise the coeval brachiopod Longtancunella chengjiangensis and the cone-shaped cnidarian-related Archotuba conoidalis, as well as rounded smaller-sized epizoans (lesser than 2 mm). A principle morphological analysis demonstrates that the ovoid and rounded organisms that often occur along the commissure of D. pista resemble small juvenile or immature brachiopods. Epibiont-bearing shells of D. pista with soft-tissue preservation demonstrate that the host brachiopods were overgrown while alive, and provide an argument for D. pista having a semi-infaunal life style with only the slim pedicle embedded in sediment. The epibiotic association sheds direct light on the ecology of Cambrian brachiopods in soft-substrate marine environments. The Chengjiang fossils demonstrate that the Early Cambrian brachiopods, as compared with recent lingulids, occupied different and a wider spectrum of ecological niches and tiers of space.     

UV Light Reveals the Diversity of Jurassic Shell Colour Patterns: Examples from the Cordebugle Lagerst?tte (Calvados,France)

Viewed under UV light the diverse and exceptionally well-preserved molluscs from the Late Jurassic Cordebugle Konservat Lagerstätte (Calvados, Normandy, France) reveal fluorescent fossil shell colour patterns predating the oldest previously known instance of such patterns by 100 Myr. Evidently, residual colour patterns are observable in Mesozoic molluscs by application of this non-destructive method, provided the shells are not decalcified or recrystallized. Among 46 species which are assigned to twelve gastropod families and eight bivalve families, no less than 25 species yielded positive results. Out of nine colour pattern morphologies that have been distinguished six occur in gastropods and three in bivalves. The presence of these variant morphologies clearly indicates a significant pre-Cenozoic diversification of colour patterns, especially in gastropods. In addition, the occurrence of two distinct types of fluorescence highlights a major difference in the chemical composition of the pigments involved in colour pattern formation in gastropods. This discovery enables us to discriminate members of higher clades, i.e. the Vetigastropoda emitting red fluorescence from the Caenogastropoda and Heterobranchia emitting whitish-beige to yellow fluorescence. Consequently, fluorescent colour patterns may help to allocate part of the numerous enigmatic Mesozoic gastropod taxa to their correct systematic position.     

Rediscovery of a lost Lagerstätte: a comparative analysis of the historical and recent Mare aux Songes dodo excavations on Mauritius

The Mare aux Songes (MAS), Mauritius, Mascarene Islands, is best known for the remarkable quality and quantity of macro- and micro-fossil remains, including those of the iconic Dodo Raphus cucullatus. It remains the most productive oceanic island fossil locality in the Indian Ocean, and is considered an integrated vertebrate bone Konzentrat-Lagerstätte. Fossil remains were first discovered in September 1865, again in the 1890s and early 1900s, but all without contextual data. The discovery of additional fossil remains in 2005 initiated an international, interdisciplinary research programme in 2006, which resulted in the first contextual analysis. However, it became clearly apparent that the nineteenth- and early twentieth-century fossil collections differed both in taphonomy and in age from late twentieth- and twenty-first-century excavations, and that it was likely that each represented a different depositional setting. Here, we provide evidence for the genesis of the MAS and show that two different fossil deposits were indeed present, each differing significantly taphonomically. Furthermore, the historical material represents a younger, seasonally desiccated, lake-shore accumulation with age range from ca. 1600 yr bp to sub-recent, whereas the 4200-year-old twenty-first-century material is more associated with a deeper, lacustrine environment.     

AN ORDOVICIAN LOBOPODIAN FROM THE SOOM SHALE LAGERSTÄTTE, SOUTH AFRICA

Abstract:  The first lobopodian known from the Ordovician is described from the Soom Shale Lagerstätte, South Africa. The organism shows features homologous to Palaeozoic marine lobopodians described from the Middle Cambrian Burgess Shale, the Lower Cambrian Chengjiang biota, the Lower Cambrian Sirius Passet Lagerstätte and the Lower Cambrian of the Baltic. The discovery provides a link between marine Cambrian lobopodians and younger forms from the Silurian and Carboniferous. The new fossil preserves an annulated trunk, lobopods with clear annulations, and curved claws. It represents a rare record of a benthic organism from the Soom Shale, and demonstrates intermittent water oxygenation during the deposition of the unit.