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DOAJ Open Access 2025
Teeth from the Middle Jurassic of Morocco reveal the oldest turiasaurian sauropods from Africa

D. Cary Woodruff, Paul M. Barrett, Driss Ouarhache et al.

Readily identifiable based on their large, “spatulate” teeth with diagnostic “heart”-shaped crowns, turiasaurians are non-neosauropodan eusauropods known from varied Jurassic and Cretaceous formations across Laurasia and Gondwana. Recently, three teeth with turiasaurian features were collected from the Middle Jurassic El Mers III Formation in the Middle Atlas Mountains of north-central Morocco. Although these teeth are superficially similar to those of the Late Jurassic Turiasaurus riodevensis from Spain, the absence of rounded denticles presence of a prominently peaked apex and a mesially flared margin, differ from other known turiasaurians. Turiasaurians have not previously been described from the El Mers III Formation, and the only named sauropod from the El Mers Group, which lacks preserved teeth, is the dubious taxon “Cetiosaurus mogrebiensis”. Due to lack of overlapping material and its lack of clear diagnostic characters, we refrain from referring these teeth to the latter, and identify them as Turiasauria indeterminate instead. These teeth represent the first definitive turiasaurian remains from Morocco, as well as the geologically oldest occurrence of Turiasauria from mainland Africa.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2024
The largest sauropodomorph skull from the Lower Jurassic Lufeng Formation of China

Qian-Nan Zhang, Lei Jia, Tao Wang et al.

The Lower Jurassic Lufeng Formation of China has long been recognized for its diverse early-diverging sauropodomorph dinosaurs, with eight genera and ten species, representing more than half the Laurasian records. In this paper, we describe a new genus and species of non-sauropodan sauropodomorph, Lishulong wangi gen. et sp. nov., from Yunnan Province in southwestern China. This new taxon is represented by a partial skeleton including the skull and nine articulated cervical vertebrae, which differs from other Lufeng forms in both cranial and cervical characteristics. It bears several autapomorphies of the nasal process, the maxillary neurovascular foramen, and the cervical neural spine. Phylogenetic analysis reveals that Lishulong is an early-diverging member of the Sauropodiformes, and the sister-taxon of Yunnanosaurus. Elucidating the novel osteology of Lishulong, it possessed the largest sauropodomorph cranial material currently identified from the Lufeng Formation, not only enriches the diversity of the Lufeng dinosaur assemblage, but also enhances our understanding of the character evolution in early-diverging sauropodiforms. Furthermore, information about paleobiogeographic distributions indicates that Early Jurassic sauropodomorphs, especially Chinese taxa, have maintained multiple dispersions and exchanges within Pangaea.

Medicine, Biology (General)
DOAJ Open Access 2023
Early Katian, Late Ordovician, heliolitine corals from southern Kuruktag in northeastern Tarim Basin of China

YU-NONG CUI, GUANG-XU WANG

Heliolitines are a major tabulate coral group, which experienced their early diversification in the Katian (Late Ordovician). Fossils of this group are well represented in the Kuruktag area of northeastern Tarim Basin, Northwest China, but detailed studies of corals from this area are still lacking. Here, we systematically describe early Katian heliolitines of the Tarim Block based on new material from the lower Katian Yuanbaoshan Formation of southern Kuruktag, which include the plasmoporellids Plasmoporella xinjiangensis and Plasmoporella grandis, the sibiriolitids Mongoliolites obliterans and Mongoliolites sp., the protoheliolitid Wormsipora sp., the proporid Acdalopora sokolovi, the pseudoplasmoporid Navoites irregularis, and the heliolitid Apekinella zeravshanica. A faunal comparison indicates that the biogeographic connections of Tarim Block are closest to Chu-Ili and South Tienshan, but relatively weaker with Qilian and North China.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2022
Evidence for Marine Consumption During the Upper Palaeolithic at “El Pirulejo” Inland Rock- Shelter (Southern Iberia Peninsula, Spain)

Yuichi I. Naito, Miriam Belmaker, Francisco J. Jiménez-Espejo et al.

During the Last Glacial Maximum and deglaciation, the Iberian Peninsula served as a faunal and human population refugium. Human foodways have always played a pivotal role in understanding social and cultural practices in prehistory. Nonetheless, the limited number of archaeological sites and human remains in this region hinders the complete understanding of these critical communities’ diet. To increase our knowledge about human consumption patterns, we selected three Magdalenian levels from the site of El Pirulejo (Southern Iberia Peninsula, Spain). These levels are characterized by a high abundance of rabbit (Oryctolagus cuniculus) remains (76–97% MNI), initially suggesting that rabbits were the primary source of protein for site inhabitants. Stable isotope analysis was conducted on two human teeth in tandem with stable isotope analysis of the rabbit teeth. Contrary to the expectations derived from the zooarchaeological analysis, rabbits were not a significant source of dietary protein. Carbon and nitrogen bulk isotopic values are the most enriched found in sampled human remains for this area and context. Our data supports aquatic food resource inclusion and increased resource diversity among Iberian hunter-gatherers during the Magdalenian. This study is consistent with previous studies that suggested a socio-economic network among human groups between inland and coastal regions in the terminal Pleistocene Southern Iberia.

Human evolution, Prehistoric archaeology
DOAJ Open Access 2021
Middle Pleistocene Variations in the Diet of <i>Equus</i> in the South of France and Its Morphometric Adaptations to Local Environments

Antigone Uzunidis

<i>Equus</i> is a very sensitive genus which has expanded over a large area and lived in Europe despite the climatic instability of the Pleistocene. Its persistence and abundance are helpful in understanding and describing environmental and climatic regional parameters. In this study, we present the result of dental mesowear and microwear analysis and post-cranial skeleton biometry on <i>Equus</i> populations located in two regions in the South of France from ten sites, corresponding to twelve assemblages dated from MIS 12 to MIS 5. The areas refer to two major climatic zones: the oceanic or subcontinental climate for the South West of France, and the Mediterranean for the South East. The first objective of this study is to integrate and compare biometric data, dental wear, and other already-published environmental proxies. The goal is to discuss the validity of horse body shape adaptations on a small geographical scale. The second objective is to describe the impact of environmental features on the horse population through time in the two regions. We observe that the <i>Equus</i> diet was quite diverse, according to microwear analysis which shows adaptations according to seasonal variations. However, they remained mostly grazers over a long period of time. Estimated body mass of <i>Equus</i> in the localities studied here varies from a mean of 468 up to a mean of 570 kg, but these variations failed to be correlated with the diet, the climatic period, or the geographical position of the horse population, probably because of the sample size or the restricted time-span or geographical scale. However, the conformation of the metapodials and the width of the third phalanges may have been linked with environmental and behavioural parameters. The width of the third phalange may be correlated with the recurrence of the snow cover, while the robustness of the metapodial co-occurs with a humid climate. Also, diet may influence the conformation of the bones, since the tall and slender horses seem to be preferentially grazers all year long and seasonally browser horses are tall and robust. Seasonally mixed-feeder horses, all coming from the Mediterranean area, were found to be smaller, perhaps in relation to a less productive environment. The correspondence of the dietary and morphometrical data could suggest high pressure on the horse population, which caused rapid body adaptation. Thus, the combination of these different proxies allows us to suggest more accurate large mammal paleoenvironmental reconstructions.

Human evolution, Stratigraphy
DOAJ Open Access 2018
Cranial anatomy of Bellusaurus sui (Dinosauria: Eusauropoda) from the Middle-Late Jurassic Shishugou Formation of northwest China and a review of sauropod cranial ontogeny

Andrew J. Moore, Jinyou Mo, James M. Clark et al.

Bellusaurus sui is an enigmatic sauropod dinosaur from the Middle-Late Jurassic Shishugou Formation of northwest China. Bellusaurus is known from a monospecific bonebed preserving elements from more than a dozen juvenile individuals, including numerous bones of the skull, providing rare insight into the cranial anatomy of juvenile sauropods. Here, we present a comprehensive description of the cranial anatomy of Bellusaurus, supplementing the holotypic cranial material with additional elements recovered from recent joint Sino-American field expeditions. Bellusaurus is diagnosed by several unique autapomorphies, including a neurovascular foramen piercing the ascending process of the maxilla at midheight, the frontal process of the nasal extending farther posteriorly onto the frontal than the prefrontal, and U-shaped medial and lateral notches in the posterior margin of the ventral process of the squamosal. Several features identified here, including a preantorbital opening in the maxilla, a stepped dorsal margin of the vomerine process of the pterygoid, and the partitioning of the dorsal midline endocranial fossae associated with the dural venous sinuses into anterior and posterior components by a transverse ridge of the parietal, are consistent with recent phylogenetic hypotheses that recover Bellusaurus as a basal macronarian or close relative of Neosauropoda. We review the current state of knowledge of sauropod cranial ontogeny, placing several aspects of the cranial anatomy of Bellusaurus in an ontogenetic context and providing explicit hypotheses of ontogenetic transformations that can be tested by future discoveries of ontogenetic variants of sauropod skulls. While scoring ontogenetically variable characters as unknown may help to alleviate the biasing effects of ontogeny on the phylogenetic position of juvenile specimens, we caution that this approach may remove phylogenetically informative character information, and argue that inference methods that are known to be less sensitive to homoplasy than equal weights parsimony (i.e., implied weights parsimony; Bayesian approaches) should also be employed.

Medicine, Biology (General)
DOAJ Open Access 2018
Nut of Juglans bergomensis (Balsamo Crivelli) Massalongo in the Miocene of North America

MACKENZIE SMITH, STEVEN R. MANCHESTER

A new occurrence of fossil butternut is recognized based on a permineralized highly scabrate walnut from the middle Miocene of western Washington, USA. The specimen fits the circumscription of Juglans bergomensis (Balsalmo Crivelli) Massalongo, a species that was widespread in Europe and Asia during the Neogene. The occurrence near Brady, Washington, supplements the previously recognized occurrence from Banks Island, Canada, indicating a distribution in mid-latitude western North America as well as Europe and Asia during the Miocene.

Paleontology, Botany
DOAJ Open Access 2015
DIVERSITY PATTERNS OF NOTOSUCHIA (CROCODYLIFORMES, MESOEUCROCODYLIA) DURING THE CRETACEOUS OF GONDWANA

Diego Pol, Juan Martín Leardi

Notosuchia is a diverse clade of Crocodyliformes that achieved a remarkable diversity during the Cretaceous. This group is particu- larly abundant in continental deposits of Gondwana throughout the Cretaceous, especially in South America. Notosuchia was first recognized as a distinct group by the early work of Gasparini in the 1970’s and in the last decades numerous discoveries and studies have increased the geographical, temporal and taxonomical scope of this clade. Here we analyze the patterns of diversity of Notosuchia during the Creta- ceous, considering their taxic and phylogenetic diversity, as well as implementing sampling corrections aiming to account for the uneven fossil record of different stages of the Cretaceous. We identify two subsequent pulses of diversification in the late Early Cretaceous and the middle Late Cretaceous, followed by two separate extinction events that occurred during the latest Cretaceous (Campanian/Maastricht- ian). We discuss the contribution of the South American, African, and Malagasy fossil records to the diversity curves, which indicates the African fossil record dominates the first pulse of diversification and the South American fossil record exclusively compose the second pulse of diver- sification. Finally, we analyze the patterns of diversity shown by the different subclades of Notosuchia throughout the Cretaceous, which reveal markedly different evolutionary dynamics of four major groups of notosuchian crocodyliforms.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2015
THE NORTH AMERICAN AVISAURIDS (AVES: ENANTIORNITHES): NEW DATA ON BIOSTRATIGRAPHY AND BIOGEOGRAPHY

Thomas A. Stidham, J. Howard Hutchison

In addition to the two described Avisaurus species (A. archibaldi Brett-Surman and Paul and A. gloriae Varrichio and Chiappe), undescribed material from the Maastrichtian contributes important morphologic, biostratigraphic, and biogeographic data on North American avisaurids. A juvenile Avisaurus specimen of an undescribed species from the Maastrichtian Hell Creek Formation of Montana reveals the presence of distal tarsals in enantiornithines and an ontogenetic stage shared with non-avian dinosaurs. All known Avisaurus fossils were deposited in a variety of habitats along the Western Interior Seaway of North America and areas more interior. The presence of other clades of birds in the Hell Creek Formation indicates that avisaurids formed only part of a diverse avifauna at the close of the Cretaceous in North America. Phylogenetic analysis of the new Maastrichtian material places these new specimens as the sister to the other known Avisaurus species within Avisauridae. This hypothesis of avisaurid relationships points to a South American origin of this clade with a dispersal or vicariant event to North America before or early in the Campanian. This event was penecontemporaneous with the Laurasian movement of alvarezsaurids and sauropods. These Montanan enantiornithine specimens represent the northern-most record of this bird clade in North America. These Maastrichtian species and specimens are from very late in the Maastrichtian and are probably the youngest known enantiornithines. The stratigraphic position of these birds with respect to the rest of the fauna indicate that their extinction was nearly synchronous with the extinction of other toothed bird clades and other vertebrates at the end of the Cretaceous. KEY WORDS. Aves. Enantiornithes. Avisaurus. Biogeography

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2014
Dating recent sediments from the subaqueous Yangtze Delta and adjacent continental shelf, China

Zhang-Hua Wang, Yong-Hong Dong, Jing Chen et al.

In this study we analyzed sediment lithology, fallout of 210Pb and 137Cs, and spheroidal carbonaceous particles (SCPs) for two short cores, YZE and CX38, obtained by gravity corer from the Yangtze River mouth offshore and adjacent continental shelf, to compare geochronological methods on the recent sediments of this area. Lithology and grain size changes in YZE suggested the re-discharging of the North Channel of the Yangtze River mouth by flood events during 1949–1954 and associated accretion in the offshore area. This event was validated by a remarkable zone of declination in both 137Cs and 210Pb activities and the absolute ages derived from the 137Cs and SCPs. In contrast, 210Pb results show obvious disturbance of grain size by sediment mixing and cannot be interpreted above 100 cm. In CX38, absolute ages for the early- and mid-1950s were derived by the 137Cs and the SCP profile respectively, which occurred in a reasonable sequence. The excess 210Pb distribution shows exponentially decreasing activities with depth, and the mean sedimentation rate agrees roughly with the one inferred from the SCP profile. We suggest that the limitation of the 210Pb method needs consideration while the SCP profile has the potential to provide a useful and independent dating method for recent Yangtze offshore and adjacent shelf sediments.

DOAJ Open Access 2013
Isotope record of environmental changes at the Skaliska Basin during the Late Glacial and Holocene

Mirosław-Grabowska Joanna

The results of isotopic investigations of the Skaliska Basin sediments are presented. Stable isotope analyses were done for authigenic carbonates from three profiles: W1 - Piotrowo-Ławniki, W2 - Sąkieły Małe, and W4 - Budzewo. The profiles contain carbonate silts at the bottom, then calcareous detritus gyttja and organic silts and peat at the top. Palynological data indicate that sediment were accumulated in the Skaliska Basin from the final phase of the Younger Dryas to the Subboreal period. The values δ18O change from ca −9.4 to −4.5‰, and δ13C values varies from −5.1 to +0.1‰. Such a large range of isotopic data reflects changing conditions in the basin during accumulation of deposits (different water levels, water temperatures, and bioproduction). Based on the results of stable isotope analyses of the carbonates, isotopic zones (Is) were defined and characterized for each profile. The results of isotopic analysis enabled reconstruction of varying environmental conditions connected with lake deepening and/or influx of water enriched in light isotopes, climatic warming, and increase of biological activity. The Late Glacial deposits are characterized by δ18O values of ca −6.5-6‰ and δ13C of ca −1‰. In the transitional time between the Late Glacial and the Holocene, δ18O systematically falls below −8‰, reflecting a substantial change in the isotopic composition of the lake water, likely caused by to inflow of melt water. During the Preboreal period the δ18O as well as the δ13C values systematically decrease and reach minima (−8.4-9.4‰ for δ18O and ca −3.5-4.7‰ for δ13C). At the beginning of the Boreal period, an increase of ca 2‰ in δ18O is noted and is associated with climatic warming. During the Atlantic period the varying trends in the δ18O record are likely connected with changing precipitation/evaporation ratios, causing changes in the isotope composition of the water. The fluctuations of the isotopic values in the upper parts of the successions probably point to shallowing of the lake due to sedimentary infill.

Paleontology, Botany
DOAJ Open Access 2012
CHRIST AND EVOLUTION: A DRAMA OF WISDOM?1

Abstract This paper argues that a genuine engagement of Christianity with evolution needs to include a discussion of Christology. Further, it develops a particular approach to Christology through a theo‐dramatic account of incarnation. The somewhat static post‐Chalcedon theological categories of divine and human natures are hard to square with contemporary evolutionary accounts of human origins. Once the divine Logos is portrayed in the active categories of Wisdom it becomes easier to envisage divine and creaturely wisdom coexisting in the person of Christ. I argue, in particular, that a focus on God's agency through a modified version of Hans Urs von Balthasar's account of theo‐drama invites participation and affirms human agency in a way that grand narratives do not. More particularly, drawing on examples from hominid evolution, contemporary discussion of paleontology and cooperative evolutionary theories, I suggest that the most convincing accounts of evolutionary biology fit into this theo‐dramatic account more readily than alternatives. As such, in the spirit of Robert Boyle, this paper deliberately blurs the categories of revealed and natural theology by arguing that we can make sense of the former through concentration on the latter.

Science, Religions. Mythology. Rationalism
DOAJ Open Access 2009
Proveniência de arenitos albianos (Grupo Itapecuru), borda leste da bacia de São Luís-Grajaú, Maranhão, usando análise de minerais pesados e química mineral

Anderson Conceição Mendes, Werner Truckenbrodt

Depósitos albianos da bacia de São Luís-Grajaú, antigamente conhecidos apenas em subsuperfície como ‘Unidade Indiferenciada’ do Grupo Itapecuru, foram recentemente encontrados ao longo do rio Itapecuru, na parte leste desta bacia. São argilitos avermelhados, esverdeados a cinzas, arenitos estratificados e maciços e subordinadamente calcários, interpretados como depósitos de delta progradante para ENE/E e ESE e conectado a uma plataforma restrita. Para determinar a proveniência de arenitos albianos, foram coletadas 18 amostras para estudos de minerais pesados (fração 0,062-0,125 mm) usando-se microscópio petrográfico convencional e microscópio eletrônico de varredura. Os arenitos foram classificados como quartzo-arenito moderadamente a bem selecionado, cimentado por dolomita, cujos principais minerais pesados são zircão (4-70%), granada (12-74%), turmalina (3-20%), estaurolita (1-9%), rutilo (1-8%) e barita (0-55%), enquanto cianita, anatásio (autigênico), anfibólio (hornblenda), andaluzita, sillimanita, espinélio e ilmenita ocorrem raramente. A maioria dos grãos é irregular angulosa, mas grãos bem arredondados, particularmente de turmalina e zircão, também estão presentes. Texturas superficiais incluem fraturas conchoidais, marcas de percussão em V e pequenos buracos, estes últimos em grãos arredondados de turmalina e zircão, enquanto feições de corrosão estão principalmente presentes em barita (cavidades rômbicas), cianita, estaurolita (superfície mamilar) e granada (facetas bem formadas por dissolução). Grãos de zircão, com texturas de zoneamento oscilatório e razões U/Th ≥ 0,5 e Zr/Hf média de 29, indicam proveniência de granitos e migmatitos, enquanto os tipos de turmalina, determinados como dravita e shorlita, são oriundos, principalmente, de metapelitos e metapsamitos aluminosos e/ou pobres em Al, com menor contribuição de granitos e rochas meta-ultramáficas. As granadas, por sua vez, são ricas em almandina e têm baixos teores dos componentes de espessartita, grossulária e piropo. Suas fontes potenciais são rochas metamórficas de baixo a médio grau e granitos. Com base em análises de minerais pesados e progradação do sistema deltaico para ENE/E e ESE, as áreas mais prováveis como fontes potenciais de arenitos albianos são o cráton São Luís, os cinturões neoproterozóicos Araguaia e Gurupi, bem como a bacia paleozóica do Parnaíba, esta fornecendo sedimentos de grãos arredondados.

Mineralogy, Paleontology
DOAJ Open Access 2008
Holostratigraphy of the Kahmah regional Series in Oman, Qatar, and the United Arab Emirates

Granier Bruno

The stratigraphic framework of the uppermost Jurassic - Lower Cretaceous interval of the Gulf area is revised using both historical and recently acquired paleontological (ammonites, calpionellids, foraminifers, 'calcareous' algae), sedimentological and sequential information. The Kahmah regional Series ranging in age from Late Tithonian to Gargasian (= middle Aptian) times is subdivided into regional stages, named from bottom to top: Rayda (with two substages, Bu Haseer and Belbazem), Salil, Zakum, Lekhwair, Kharaib, Hawar, and Shu'aiba. The Kahmah rests either on strata representing the Habshan regional Stage, which is the last term of the Sahtan regional Series (locally absent due to a stratigraphic hiatus in basinal areas), or on much older strata; it is followed either by the Bab regional Stage (locally absent due to a stratigraphic hiatus on platform areas), or by the Sabsab regional Substage (the lowermost part of the Nahr Umr regional Stage), both of which are assigned the Wasi'a regional Series. The Kahmah succession (as well as those of the Sahtan below and the Wasi'a above) is discontinuous, i.e. punctuated by sedimentary hiatuses due to forced regressions, some of significant importance (in the Zakum or in the Bab, and those bounding the Hawar and the Shu'aiba).

Geology, Paleontology
DOAJ Open Access 1999
Die mesophytische Flora der Saurierlagerstätte am Tendaguru (Tansania) Erste Ergebnisse

E. Kahlert, S. Schultka, H. Süß

Abgesehen von einem unreifen Araukarienzapfen, der 1927 von Gothan kurz beschrieben wurde, werden erstmalig Pflanzenreste aus den Jura-Kreide-Grenzschichten des Tendaguru bekannt gemacht. Verkieselte Hölzer vor allem aus kreidezeitlichen Schichtabschnitten repräsentieren die für den Jura üblichen Koniferengruppen wie Taxodiaceae, Cupressaceae und Taxaceae. Daneben konnten Ginkgoaceae nachgewiesen werden. Fusit ist nicht selten, meist aber sehr schlecht erhalten, bis auf ein Stück, das die Merkmale einer wahrscheinlich neuen Art von Glyptostroboxylon, einer Taxodiacee, zeigt. Naturmazerate von Kutikulen sind in den mittleren Saurier-Mergeln (tieferes Kimmeridge) häufig und können möglicherweise Ginkgophyten des Baiera/Sphenobaiera-Typs zugerechnet werden. Damit scheint die Flora von Tendaguru auf den ersten Blick von Gymnospermen extrem stark dominiert zu sein. Diese Dominanz ist wahrscheinlich auf taphonomische Prozesse und auf die selektive Probennahme während der Grabungsexpedition in den Jahren 1909–1913 zurückzuführen. So erscheinen neue Profilaufnahmen im Gelände unumgänglich, um ein differenzierteres Bild der jurassisch-kretazischen Flora des östlichen Afrika &amp;ndash; die die Ernährungsgrundlage der meisten Dinosaurier vom Tendaguru bildete &amp;ndash; zu entwickeln und phytogeographische Beziehungen genauer fassen zu können.Little is known about the Jurassic flora of East Africa. Therefore a preliminary account on plant remains from the well-known „Saurierlagerstätte” of Tendaguru is presented. Specimens of silicified wood represent typical conifers, such as Taxodiaceae, Cupressaceae and Taxaceae, but also demonstrate the presence of Ginkgoales. Fusite is very common, but mostly not well preserved, except for one specimen which shows the characteristics of possibly a new species of the Taxodiacean genus Glyptostroboxylon. Natural macerated cuticules are abundant in the „middle Saurier-Mergel” (Lower Kimmeridgian) and they at least in part seem to belong to Ginkgophytaleans of the Baiera/Sphenobaiera-group. At first glance the composition of the flora of Tendaguru seems to be biased towards a predominance of Gymnosperms. This is not only a result of taphonomical processes, but also of selective sampling in 1909–1913. Preliminary observations support the opinion that further field work must be carried out if we would like to obtain a clearer „picture” of the Jurassic-Cretaceous flora that formed the diet of herbivorous dinosaurs.doi:10.1002/mmng.1999.4860020114

DOAJ Open Access 2006
Les algues vertes (phylum Viridiplantae), sont-elles vieilles de deux milliards d'années ?

Teyssèdre Bernard

Bernard TEYSSÈDRE est professeur émérite, ancien directeur d'une unité CNRS/Université de Paris en Sciences Humaines et Sociales. Il a dirigé une école doctorale en Arts et Sciences de l'Art et l'Institut d'Esthétique des Arts contemporains. Docteur en Histoire et en Philosophie, son dessein profond est la quête des sources, celle de notre imaginaire avec ses ouvrages sur la Naissance du Diable et de l'Enfer, de Babylone aux grottes de la Mer Morte ou sur les Anges, les Astres et les Cieux, comme celle des débuts de toute forme de vie. Avec une surprenante fiction politico-romanesque autour du sulfureux tableau de COURBET l'Origine du Monde, pensait-il déjà à l'enquête qu'il allait mener sur les temps oú la vie se cachait, "La vie invisible" oú il passe de l'archéologie de nos croyances à la quête scientifique de nos origines ? Passionné depuis toujours par les Sciences de l'évolution, il possède sur les fossiles et leur descendants des connaissances quasi-encyclopédiques que bien des spécialistes peuvent lui envier. L'étude des trois premiers milliards d'années de l'histoire de la vie est récente et en pleine évolution. 90% des fossiles précambriens ont été découverts depuis moins de 20 ans. Bernard TEYSSÈDRE a intégré dans "La vie invisible" les données de la paléontologie, de la biochimie et de la phylogénie moléculaire. C'est la première synthèse de ce qu'on appelle actuellement la Géologie intégrative. On se prend à apprécier la lecture avec un style dont on a perdu l'habitude, d'un ouvrage que seuls les anglo-saxons semblaient capables de proposer. L'ouvrage présenté ici a pour base un différend qui oppose l'auteur à Andrew KNOLL, qui situe l'apparition des algues vertes vers 750 Ma. Bernard TEYSSÈDRE analyse ce problème par les méthodes qu'il préconisait dans "La vie invisible" combinant à la paléontologie descriptive traditionnelle, les analyses ultrastructurales et biochimiques et confrontant ces résultats avec ceux de la phylogénie moléculaire. Manié avec discernement et compétence, cet outil ne permet certes pas d'établir une taxinomie exacte, mais d'écarter les taxinomies erronées basées sur des convergences et de déterminer la succession des points nodaux dans l'évolution d'une lignée. Ce qui l'amène à conclure que les Pyramimonadales seraient apparues avant 1500 Ma, et que le moment de divergence entre les algues vertes et les algues rouges serait proche de 2000 Ma). La date de 750 Ma, objet du litige, est bien loin... L'auteur nous promet une Paléontologie du Précambrien à la lumière de la phylogénie moléculaire. Cet ouvrage très ciblé nous fait espérer une prochaine synthèse des nouvelles données sur l'évolution de la vie depuis les origines.

Geology, Paleontology
DOAJ Open Access 1999
Palynology of the dinosaur beds of Tendaguru (Tanzania) &amp;ndash; preliminary results

E. Schrank

The Tendaguru Beds, southeastern Tanzania, have yielded two palynological assemblages of Kimmeridgian to Tithonian age: (1) the Anapiculatisporites-Densoisporites-Trisaccites assemblage from the Middle Saurian Beds and (2) the Barbatacysta-Pareodinia assemblage from the overlying Smeei Beds. A third assemblage with Rhizophagites and rare angiosperm pollen from the Upper Saurian Beds is contaminated by recent and subrecent material.The Anapiculatisporites-Densoisporites-Trisaccites assemblage is characterized by the presence of freshwater algae (Ovoidites), pteridopyhtic-bryophytic spores and gymnosperm (conifer) pollen, with Classopollis as the most abundant element. Among the rare elements of this assemblage is the questionable dinoflagellate Mendicodinium? quadratum, possibly a Kimmeridgian-Tithonian marker. The miospores show palaeobiogeographic links to Southern Gondwana, especially Madagascar, Australia, Argentina and India. Deposition of this assemblage took place in an aquatic environment with strong palynological influx from a terrestrial source and questionable marine influence.The Barbatacysta-Pareodinia assemblage contains a considerable number of dinoflagellates suggesting deposition in a marine environment. The terrestrially-derived miospores are impoverished and dominated by conifer pollen, while pteridophytic-bryophytic spores form a very subordinate element or are absent.Die Tendaguru-Schichten, Südost-Tansania, haben zwei palynologische Assoziationen, deren Alter als Kimmeridge bis Tithon interpretiert wird, geliefert. Die Anapiculatisporites-Densoisporites-Trisaccites-Assoziation stammt aus den Mittleren Saurierschichten, und die Barbatacysta-Pareodinia-Assoziation charakterisiert die darüberlagernden Smeei-Schichten. Eine dritte Vergesellschaftung mit Rhizophagites und seltenen Angiospermen-Pollen aus den Oberen Saurierschichten ist durch rezentes bis subrezentes Material kontaminiert.Die Anapiculatisporites-Densoisporites-Trisaccites-Assoziation ist durch die Anwesenheit von Süßwasser-Algen (Ovoidites), Pteridophyten-Bryophyten-Sporen und Gymnospermen-Pollen (Koniferen) gekennzeichnet mit Classopollis als dem häufigsten Element. Zu den seltenen Elementen dieser Assoziation gehört der fragliche Dinoflagellat Mendicodinium? quadratum, der möglicherweise als leitend für das Kimmeridge-Tithon angesehen werden kann. Die Miosporen zeigen paläobiogeographische Verbindungen nach Südgondwana, besonders nach Madagaskar, Australien, Argentinien und Indien. Das Ablagerungsmilieu dieser Assoziation war aquatisch mit starker Zufuhr von terrigenem Material, während mariner Einfluß fraglich ist.Die Dinoflagellaten-führende Barbatacysta-Pareodinia-Assoziation wurde in einem marinen Milieu gebildet, in dem die Zufuhr terrigener Palynomorphe reduziert und im wesentlichen auf Koniferen-Pollen beschränkt war, während Pteridophyten-Bryophyten-Sporen nur sehr untergeordnet vorkommen oder ganz fehlen.doi:10.1002/mmng.1999.4860020113

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