West Gondwana

The illaenid trilobite Vysocania is widely represented in the Upper Ordovician of the Czech Republic, Portugal and Spain, and is one of the most characteristic taxa in the high-latitude peri-Gondwana palaeobiogeographical region to which it is endemic. Three species of the genus that were formerly assigned to Stenopareia and Zetillaenus, from the Czech Republic and Spain respectively, are herein revised, and a new species is described from the Czech Republic. The genus Octillaenus, of which a new species is described from the Upper Ordovician of Morocco, is considered to have arisen from Vysocania through paedomorphic (neotenic) processes. The relationships between Vysocania, Octillaenus, Stenopareia and Zetillaenus are reviewed and the criteria used in the definition of these taxa discussed. Species assigned to Vysocania are V. vaneki (type-species), V. iberica, V. moraveci sp. nov. and V. panderi; species assigned to Octillaenus are O. hisingeri (type-species) and O. marocanus sp. nov. Vysocania appears for the first time in the lower Berounian (Sandbian) and has its last undoubted record in the upper Berounian (upper Katian); Octillaenus is presently restricted to the Kralodvorian (upper Katian). •

For 130 years dinosaurs have been divided into two distinct clades – Ornithischia and Saurischia.

This dissertation looks at the earliest evolution of the clade Dinosauria by focusing upon the interrelationships of the major subsidiary clades within it. It does this following examination, comparison and description of early dinosaur material, and by utilising modern phylogenetic analysis techniques, to rigorously and objectively test the fundamental groupings within the clade Dinosauria using a newly compiled dataset of early dinosaurs and other dinosauromorphs (= close dinosaur relatives). The current consensus on how the principal clades within Dinosauria (Theropoda, Sauropodomorpha and Ornithischia) are related to one another is challenged by the results of these analyses. This study finds, for the first time, a sister-group relationship between Ornithischia and Theropoda, here termed Ornithoscelida. Consequently, a new definition for Dinosauria is presented, as the historic definition would exclude all members of Sauropodomorpha from the clade. As well as this, I propose revisions to the definitions of each of the principal dinosaurian sub-divisions and propose a new timeframe and geographic setting for the origin of Dinosauria. These new hypotheses force re-evaluations of early dinosaur cladogenesis and character evolution, suggest the independent acquisition of hypercarnivory in multiple dinosaur groups and offers an explanation for many of the anatomical features previously regarded as striking convergences between theropods and early ornithischians.

As well as presenting new anatomical data on many early dinosaurs and dinosauromorphs, including a comprehensive re-description of the postcranial anatomy of Lesothosaurus diagnosticus (Chapter 2), and a new anatomical dataset of early dinosaurs (the largest ever compiled), this thesis goes on to implement the new dataset to investigate a number of important outstanding questions about early dinosaur evolution and provides new lines of enquiry for future workers to pursue. The results of this thesis reveal the oldest known members of the dinosaurian clades Theropoda and Sauropodomorpha (Chapter 6), as well as a new clade within Ornithischia; a taxon previously thought to represent a derived theropod has been recovered as a potential ‘missing link’ between theropods and ornithischians using the new dataset.
This work now provides a unique tool for the assessment of the phylogenetic affinities of early dinosaurs and dinosauromorphs and, once published, will hopefully become the benchmark dataset for palaeontologists working in this area.

The new ellipsocephaloid trilobite species Kingaspidoides spinirecurvatus has a spectacular morphology because of a unique set of two long and anteriorly recurved spines on the occipital ring and the axial ring of thoracic segment 8. Together with the long genal spines this whimsical dorsally directed spine arrangement is thought to act as a non-standard protective device against predators. This is illustrated by the body posture during different stages of enrolment, contrasting with the more sophisticated spinosities seen in later trilobites, which are discussed in brief. Kingaspidoides spinirecurvatus from the lower–middle Cambrian boundary interval of the eastern Anti-Atlas in Morocco has been known for about two decades, with specimens handled as precious objects on the fossil market. Similar, but far less spectacular, spine arrangements on the thoracic axial rings are known from other ellipsocephaloid trilobites from the Anti-Atlas of Morocco and the Franconian Forest region of Germany. This suggests that an experimental phase of spine development took place within the Kingaspidoides clade during the early–middle Cambrian boundary interval.

The new ellipsocephaloid trilobite species Kingaspidoides spinirecurvatus has a spectacular morphology because of a unique set of two long and anteriorly recurved spines on the occipital ring and the axial ring of thoracic segment 8. Together with the long genal spines this whimsical dorsally directed spine arrangement is thought to act as a non-standard protective device against predators. This is illustrated by the body posture during different stages of enrolment, contrasting with the more sophisticated spinosities seen in later trilobites, which are discussed in brief. Kingaspidoides spinirecurvatus from the lower–middle Cambrian boundary interval of the eastern Anti-Atlas in Morocco has been known for about two decades, with specimens handled as precious objects on the fossil market. Similar, but far less spectacular, spine arrangements on the thoracic axial rings are known from other ellipsocephaloid trilobites from the Anti-Atlas of Morocco and the Franconian Forest region of...

0. Abstract                               1
1. Introduction                               2
2. Paleomagnetic constraints on the Neoproterozoic supercontinent  3
2.1 1100–900 Ma: Laurentia and Baltica               3
2.2 1100–900 Ma: Amazonian craton (AC) and Baltica       3
2.3 1100–900 Ma: Kalahari craton               5
2.4 1100–900 Ma: Congo–Sao Francisco (CSF) craton       5
2.5 1075–990 Ma Siberian craton                       5
2.6 India 1100–1000 Ma                               5
3. True polar wander?                       5
4. The breakup of Rodinia: 800–700 Ma               5
5. 580 Ma and younger reconstructions               7
6. Conclusions                             7

In this study, we utilize multiple thermochronometric methods, including apatite and zircon fission track, (U-Th)/He, and zircon U-Pb, to evaluate the cooling history and provenance of sedimentary strata of the late Carboniferous to Late Permian eastern Paganzo basin and adjacent basement rocks (Argentina). The strata in the study area represent a long-lived, composite basin system that is interpreted to have experienced multiple periods of deformation, and to have received sediment from a number of different source terranes. These strata are well exposed in the Sierra de Chepes of west-central Argentina. New thermochronometric data and field observations, together with published data from the surrounding mountains, allow us to reconstruct: (1) the cooling history of the underlying basement rocks and the highlands surrounding the basin, (2) the thermal history of the source areas that provided sediment to the basin, and (3) the timing of structural inversion of the basin. Our data suggest that parts of the Sierra de Chepes were rapidly exhumed in Late Devonian–Carboniferous times; these exhuming areas supplied sediment to the adjacent basin. In contrast, the overlying red-bed strata originated from a slowly exhuming region located farther east or north of the basin within the Pampean orogenic belt or the Famatinian belt, respectively. Burial by latest Carboniferous and younger strata and an elevated geothermal gradient resulted in heating of the underlying Upper Carboniferous strata and underlying granitoid basement to temperatures between 80 °C and 140 °C. During Triassic time, the eastern Paganzo basin was structurally inverted; this event was marked by rapid cooling and may be related to regional extension and the development of rift basins to the west. The basement and the Upper Paleozoic strata of the eastern Paganzo basin in the study area have remained below 50 °C since latest Jurassic–Early Cretaceous times and are characterized by very slow cooling. Results of this study provide a thermochronometric view along an ∼330 m.y. path defining the geologic evolution of the eastern Paganzo basin and the upper crust of west-central Argentina.

The provenance of sandstones deposited in the late Paleozoic Tepuel-Genoa Basin is analyzed in this paper. Five sections were sampled in Esquel, Sierra de Tepuel, Sierra de Tecka, El Molle, and Río Genoa areas for petrographic and geochemical studies. The sandstones in the Tepuel-Genoa Basin are dominated by feldspathic litharenites and litharenites, showing lithic fragments of volcanic and sedimentary rocks in the Valle Chico Formation and medium-to high-grade metamorphic rock clasts in the rest of the units. Detrital modes of seventy-five sandstones samples from the Valle Chico, Pampa de Tepuel, Mojón de Hierro, and Río Genoa formations were counted and analyzed. Seven modal components have discriminant value for identifying provenance areas (Qm, Qi, Lv, Lmm-h, Lm-Lp, Lm, Qpm). These modal components allow identification of three petrofacies: 1. Quartzose-lithic (Qm 69 Lv 2 Lm 29), 2. Quartzose (Qm 89 Lv 4 Lm 7) and 3. Volcanic-sedimentary (Qm 60 Lv 38 Lm 1). The quartzose-lithic petrofacies is mainly composed of monocrystalline quartz, medium-and high-grade metamorphic clasts and polycrystalline quartz with cataclastic texture, this assemblage is interpreted as being derived from the crystalline rocks that form the Deseado Massif. The quartzose petrofacies is composed of monocrystalline quartz with scarce contributions of metamorphic clasts and traces of volcanic fragments; the provenance area is ascribed to sedimentary terrains, which most likely covered part of the Deseado Massif. The volcanic-sedimentary petrofacies is comprised of volcanic (acidic and intermediate rocks) and sedimentary (sandstone and mudstone) clasts, with discrete amounts of quartz grains with idiomorph shapes and embayments. This assemblage may correspond to material supply from the Devonian-Early Carboniferous accretionary complex developed in Chile or the unroofing of the western volcanic arc located in the central part of Patagonia. The validity of the three defined petrofacies was evaluated using Principal Component Analysis and triangular compositional diagrams; both methods show good separation and lack of overlap between the three petrofacies. Major (Si, Al, Fe, Na, K) and trace-REE elements (Zr, Th, Sc, Hf) were used to improve the petrographic information. The relation SiO 2 against K 2 O/Na 2 O indicates that the Pampa de Tepuel and the Mojón de Hierro formations correspond to a passive margin, while the Valle Chico and Río Genoa formations represent different types of active continental margins. The Th/Sc and Zr/Sc ratios and the Th-Hf-Co distributions indicate that the sandstones of the Tepuel Group were formed from rocks compatibles with the average composition of the upper continental crust.

Der Präkambrische Superkontinent Rodinia 3
Anfahrt Red Rock Parkway         4
Feldbuchabschrift und Handstück         5
Fotos vom Canyon                 6
mud cracks -Trockenrisse                 8
Wasserfall                       10
Wellenrippeln               11
„Findlinge“                       13 - 19

0. ABSTRACT                                                                               1
1. INTRODUCTION                                                                       2
2. THE RODINIA HYPOTHESIS                                                       3
3. Break-up of Rodinia                                                               3
4. Assembly of southern Gondwana                                       4
5. Rodinia and true polar wander                                               4
6. LOW LATITUDE GLACIATION AND THE SNOWBALL EARTH 5
7. The snowball Earth hypothesis                                                 5
8. Criticisms of the snowball hypothesis                                 5
9. Snowball Earth and early animal evolution                         6
10. CLOSING REMARKS                                                                 6

A diverse microphytoplankton assemblage recovered from terrestrial deposits of the La Veteada Formation, north of the La Rioja Province, Paganzo Basin, Argentina, is described and illustrated. The~180 m thick sedimentary type section of the unit in the Los Colorados anticline is composed of a basal gray silcrete covered by gypsum beds and a thick succession of purple mudstones inter-layered with varicolored fine sandstone sheets and laminated yellowish dolomites. The aquatic assemblage is mainly characterized by a great variety of Syndesmorion stellatum (Fijałkowska) Foster et Afonin coenobia, recorded for the first time in the late Permian Gondwanic realm. All the previous morphotypes described for this chlorophycean alga are recognized in this assemblage, and new polymorph-coenobia are described and illustrated. The diversity of coenobia morphotypes of this alga is likely to reflect response to stress conditions. The genera Maculatasporites and Mehlisphaeridium are commonly present, and their algal origin is discussed. Maculatasporites gondwanensis, Maculatasporites amplus, Mehlisphaeridium parvum, and Mehlisphaeridium regulare and Mehlisphaeridium sp. are also described and illustrated. Representatives of the zygnematacean algae, Brazilea scissa, Brazilea plurigenus, Brazilea sp. A, Tetraporina tetragona, ?Lecaniella sp., as well as large clusters of sphaeromorphs incertae sedis chlorophyta algae, are described. In addition, planar colonial chlorococcalean Pediastrum-like forms suggesting hydrodictyaceaen algae are recorded for the first time in late Paleozoic strata of Argentina, and the zygnematalean affinity of Reduviasporonites chalastus as green algae is discussed. The highly diverse La Veteada microphytoplanktonic assemblage is composed by algae that grew in hypersaline lacustrine environment together with species commonly associated with either fresh or brackish water conditions; presumably these taxa were washed in after heavy rainfall and/or flooding events. In general terms, the land-derived palynological composition of the La Veteada assemblage at Central Famatina Range reflects parent vegetation adapted to arid or semi-arid climate as reported from late Guadalupian to late Lopingian in the Paganzo Basin. The whole palynological composition suggests a Lopingian age for the La Veteada Formation at its stratotype, based on the stratigraphic range of all the land-derived miospore species recognized, resulting younger than assemblages assigned to the Lueckisporites-Weylandites Biozone (LW: Wordian-Capitanian). Therefore, it is the youngest Permian palynofloral assemblage recorded up to now in Argentina and South America.

At the east of the Ventana Ranges, Buenos Aires, Argentina, outcrops the Carboniferous-Permian Pillahuincó Group (Sauce Grande, Piedra Azul, Bonete and Tunas Formation). We carried out an Anisotropy of Magnetic Susceptibility (AMS) study on Sauce Grande, Piedra Azul and Bonete Formation that displays ellipsoids with constant Kmax axes trending NW–SE, parallel to the fold axes. The Kmin axes are orientated in the NE–SW quadrants, oscillating from horizontal (base of the sequence-western) to vertical (top of the sequence-eastern) positions, showing a change from tectonic to almost sedimentary fabric. This is in concordance with the type and direction of foliation measured in petrographic thin sections which is continuous and penetrative to the base and spaced and less developed to the top. We integrated this study with previous Tunas Formation results (Permian). Similar changes in the AMS pattern (tectonic to sedimentary fabric), as well as other characteristics such as the paleo-envi...

At the east of the Ventana Ranges, Buenos Aires, Argentina, outcrops the Carboniferous-Permian Pillahuincó Group (Sauce Grande, Piedra Azul, Bonete and Tunas Formation). We carried out an Anisotropy of Magnetic Susceptibility (AMS) study on Sauce Grande, Piedra Azul and Bonete Formation that displays ellipsoids with constant Kmax axes trending NW–SE, parallel to the fold axes. The Kmin axes are orientated in the NE–SW quadrants, oscillating from horizontal (base of the sequence-western) to vertical (top of the sequence-eastern) positions, showing a change from tectonic to almost sedimentary fabric. This is in concordance with the type and direction of foliation measured in petrographic thin sections which is continuous and penetrative to the base and spaced and less developed to the top. We integrated this study with previous Tunas Formation results (Permian). Similar changes in the AMS pattern (tectonic to sedimentary fabric), as well as other characteristics such as the paleo-envi...

At the east of the Ventana Ranges, Buenos Aires, Argentina, outcrops the Carboniferous-Permian Pillahuincó Group (Sauce Grande, Piedra Azul, Bonete and Tunas Formation). We carried out an Anisotropy of Magnetic Susceptibility (AMS) study on Sauce Grande, Piedra Azul and Bonete Formation that displays ellipsoids with constant Kmax axes trending NW–SE, parallel to the fold axes. The Kmin axes are orientated in the NE–SW quadrants, oscillating from horizontal (base of the sequence-western) to vertical (top of the sequence-eastern) positions, showing a change from tectonic to almost sedimentary fabric. This is in concordance with the type and direction of foliation measured in petrographic thin sections which is continuous and penetrative to the base and spaced and less developed to the top. We integrated this study with previous Tunas Formation results (Permian). Similar changes in the AMS pattern (tectonic to sedimentary fabric), as well as other characteristics such as the paleo-envi...

Supplementary File 1. List of the material identified in material from boreholes YCF.CO1, YCF.CO2 and YCF.CO3, Santiago Temple, Córdoba Province, Argentina. The species that are recorded for the first time in the Chacoparaná Basin are illustrated (Figs I–V). Species representing a nomenclatural innovation (Plates 1–3) are described and illustrated in the main text.

This paper presents an analysis of the spatiotemporal distribution and composition of a volcanosedimentary complex, which has recorded a significant episode of carbonate productivity embedded in a thick and monotonous, turbiditic-dominated rift succession. The studied nucleation of a microbial–skeletal carbonate factory is middle Cambrian in age and situated at Sidi-Saïd-Maâchou, an uplifted rift shoulder of the Moroccan Coastal Meseta located at the junction of several graben segments, where an alkaline basaltic magma was extruded along fissures or intruded as sills and dikes. The geometry and facies of the skeletal calcarenite sheets, composed of hiatal shelled accumulations separated by microbial mats, is comparable to those of the Brèche à Micmacca recorded across the lower-middle Cambrian transition in the Anti-Atlas and High Atlas. The patchy and diachronous distribution of these 'anomalous' carbonate factories, spatially and temporally associated with volcanic episodes, marks the northward migration of active rifting structures throughout the Moroccan margin of West Gondwana.