Brachiopod community paleoecology, paleobiogeography, and depositional topography of the Devonian Onondaga Limestone and correlative strata in eastern North America

The Emsian? through early Eifelian Onondaga Limestone of the Appalachian Basin was deposited in a topographic basin and on the carbonate platform which surrounded the basin on the west, north, and northeast. Onondaga strata thin from the platform into the basin. Two sedimentary cycles are present in the sub-Tioga Onondaga of eastern North America. The Edgecliff-Amherstburg represents an interval of transgression, in which epeiric seas spread over much of eastern North America. During the Nedrow-Lucas regression, the interior of the carbonate platform became restricted, resulting in the deposition of evaporites. The Moorehouse-Anderdon transgression continued through the deposition of the Tioga Bentonite, followed by the pre-Speeds-Dundee regression from the craton. Early Eifelian Appalachian Basin Onondaga brachiopod communities, arranged from nearshore to offshore, include the Atrypid-Megakozlowskiella, Atrypid-Levenea, Chonetid, Atlanticocoelia, Ambocoeliid, and Truncalosia Communities. The Onondaga-age Eastern Americas Realm is divided into the Appohimchi Province in the Appalachian Basin and the Michigan Basin-Hudson Bay Lowland Province in the Midwest. The provincial assignment of the James Bay region of Ontario is uncertain; the Eastern Townships of Quebec are near the boundaries both of the two provinces of the Eastern Americas Realm, and of the Eastern Americas Realm and the Old World Realm, the latter realm being probably in the Canadian Maritime Provinces.     

Paleoecological and paleobiogeographic considerations of Ordovician graptolites from the Cordillera Oriental,Jujuy Province,Argentina

We analyse new paleoecological data from South American graptolite records to understand the patterns that influence the space-tempo distribution of the group. A cluster analysis including taxa from the Baltograptus cf. B. deflexus and Didymograptellus bifidus Zones is carried out to evaluate the paleogeographic relationships between north-western Argentina and the other regions in the world. Three different biofacies were recognised in the Acoite Formation. The first biofacies takes place in the lower part of the unit, corresponding to pelitic levels (Tetragraptus phyllograptoides and Tetragraptus akzharensis Zones), and it is represented by pandemic forms. The other two biofacies belong to the endemic or neritic shallow water environments, and develop in deposits corresponding to the middle part of the Acoite Formation (bottom of the Baltograptus cf. B. deflexus Zone) in the Sierra de Aguilar, and in the upper half of the unit exposed in the Los Colorados area (D. bifidus Zone), respectively. The statistical analysis highlight the paleobiogeographic relationship between north-western Argentina and south-western China during the middle-upper Floian (Baltograptus cf. B. deflexus and D. bifidus Zones), and it supports the hypothesis that during the Early Ordovician north-western Argentina was located in the middle to high latitudes, included in the cold water faunal realm.     

Paleobiota from the Deccan volcano-sedimentary sequences of India: paleoenvironments,age and paleobiogeographic implications

Paleobiotic assemblages from the Deccan infra- and intertrappean beds are reviewed in great detail. Three distinct paleoenvironments (fluvio-lacustrine/terrestrial, brackish water and marine) have been identified within the infra- and intertrappean biotic assemblages of peninsular India. Recently, marine incursions have been recorded in a few of the Deccan intertrappean beds exposed in central and south-eastern India. The intertrappean beds have yielded marine planktic foraminiferans and freshwater/brackish water ostracods. The affinities of the paleobiotas are commonly considered to show a mixed pattern resulting from the addition of Gondwanan and Laurasian elements to endemic Indian taxa. During the last four decades, various biogeographic models (southern and northern connections) have been proposed to explain the presence of anomalous biogeographic biota in the Late Cretaceous of India. Based on the recovered fauna and flora assemblages, the Cretaceous–Paleogene boundary has been marked and a Late Cretaceous to Early Paleocene age has been assigned to these Deccan volcano-sedimentary sequences.     

Biostratigraphic subdivision and correlation of Uppermost Carboniferous/Lower Permian sediments in the Southern Alps: Fusulinoidean and condont faunas from the Carnic Alps (Austria/Italy), Karavanke Mountains (Slovenia), and Southern Urals (Russia)

Summary In order to establish a refined biostratigraphic subdivision and correlation of the Uppermost Carboniferous/Lower Permian deposits of the Southern Alps (Carnic Alps, Karavanke Mountains; Austria/Italy/Slovenia), two major microfossil groups (fusulinoideans, conodonts) were investigated within the same sample. The fusulinoidean species diversity (71 species, including five new species and three new subspecies) and generic composition were reviewed and complemented. Additionally, the data on fusulinoidean assemblages were supplemented by co-occurring conodont faunas (seven species). Accompanying studies on material from the type sections of the Southern Urals (Russia) were made to improve the biostratigraphic correlation with the Russian standard zonation and to discuss paleobiogeographical aspects of the faunal associations. An integrated microfacies analysis of the sampled material in the Southern Alps serves to evaluate the relationships between certain genera and specific microfacies types. The fusulinoidean fauna of the Lower “Pseudoschwagerina” Limestone is of late Gzhelian age. The Carboniferous/Permian boundary is close to the base of the Grenzland Formation, which covers the entire Asselian and a part of the Sakmarian. The Upper “Pseudoschwagerina” Limestone and Trogkofel Limestone are Lake Sakmarian to Artinskian. The studies sequences in the Karavanke Mountains. formerly known as “carbonate and clastic Trogkofel beds”, correlate to the Lower “Pseudoschwagerina” Limestone, respectively with parts of the Grenzland Formation. Due to the lithologic differences, new formation names (Dolzanova Soteska Fm., Born Fm.) were introduced for the so-called “Trogkofel” Limestone along the Dolzanova Soteska. Whereas late Gzhelian/Asselian fusulinoidean faunas of the Southern Alps correspond to the Southern Uralian faunas to a large extent, Sakmarian and Artinskian faunas reveal an increasing divergence in species and genus composition. Climatic as well as geographic barriers may have prevennted the dispersal of Paleotethyan taxa into the Southern Urals. Biostratigraphic correlation of Sakmarian to Artinskian deposits is therefore possible only on the basis of the sparse conodont faunas.     

New Glyptodont from the Codore Formation (Pliocene), Falcón State, Venezuela, its relationship with theAsterostemma problem, and the paleobiogeography of the Glyptodontinae

One of the basal Glyptodontidae groups is represented by the Propalaehoplophorinae (late Oligocene — middle Miocene), whose genera (Propalaehoplophorus, Eucinepeltus, Metopotoxus, Cochlops, andAsterostemma) were initially recognized in Argentinian Patagonia. Among these,Asterostemma was characterized by its wide latitudinal distribution, ranging from southernmost (Patagonia) to northernmost (Colombia, Venezuela) South America. However, the generic assignation of the Miocene species from Colombia and Venezuela (A.? acostae, A. gigantea, andA. venezolensis) was contested by some authors, who explicitly accepted the possibility that these species could correspond to a new genus, different from those recognized in southern areas. A new comparative study of taxa from Argentinian Patagonia, Colombia and Venezuela (together with the recognition of a new genus and species for the Pliocene of the latter country) indicates that the species in northern South America are not Propalaehoplophorinae, but represent the first stages in the cladogenesis of the Glyptodontinae glyptodontids, the history of which was heretofore restricted to the late Miocene — early Holocene of southernmost South America. Accordingly, we propose the recognition of the new genusBoreostemma for the species from northern South America and the restriction ofAsterostemma to the Miocene of Patagonia. Thus, the available data indicate that the Glyptodontinae would in fact have arisen in the northernmost regions of this continent. Their arrival to more southerly areas coincides with the acme of the “Age of Southern Plains”. The Propalaehoplophorinae are geographically restricted to Patagonia.     

西藏南部白垩纪岗巴群的双壳类及其生物地理意义

描述双壳类化石４２种,建立１０新种：Ｇｒａｍｍａｔｏｄｏｎ（Ｎａｎｏｎａｖｉｓ）ｍｉｎｕｍ ｓｐ．ｎｏｖ．,Ｐｒｏｐｅａｍｕｓｓｉｕｍ（Ｐ．）ｔｉｂｅｔｅｎｓｐ ｅｐ．ｎｏｖ．,Ｐｌｉｃａｔｕｌａ ｈｉｍａｌａｙｅｎｓｉｓ ｓｐ．ｎｏｖ．,Ｐｓｅｕｄｏｌｉｍｅａ ｄｕｏｄｅｃｉｃｏｓｔａｔａ ｓｐ．ｎｏｖ．,Ｐｙｃｎｏｄｏｎｔｅ（Ｐｈｙｇｒａｅａ）ｇａｍｂａｅｎｓｉｓ ｓｐ．ｎｏｖ．,Ｎｏｔｏｔｒ     

First Miocene fossils of Vivianiaceae shed new light on phylogeny,divergence times,and historical biogeography of Geraniales

The origin of Geraniales (approximately 900 species in three families: Geraniaceae, Melianthaceae, and Vivianiaceae) is traced back to the Cretaceous of Gondwana, yet their geotemporal history is largely unknown because of a limited fossil record and incomplete phylogenies. In the present study, we provide the first fossil record of Vivianiaceae and a highly resolved molecular phylogeny for all extant Geraniales genera. Our results support the hypothesis that five (instead of three) families should be recognized in the order Geraniales: Francoaceae A. Juss. (Francoa, Greyia, Tetilla), Geraniaceae Juss. (Erodium, Geranium, Monsonia, Pelargonium), Hypseocharitaceae Wedd. (monogeneric), Melianthaceae Horan. (Bersama, Melianthus), and Vivianiaceae Klotzsch (Balbisia, Rhynchotheca, Viviania). The four major lineages (i.e. Geraniaceae, Francoaceae + Melianthaceae, Hypseocharitaceae, Vivianiaceae) all originated within a narrow time frame during the Eocene (36.9–49.9 Mya) based on the five fossil calibration points. The divergence of most of the extant genera occurred much later, from the Miocene onwards. The South American–South African disjunction in Francoaceae apparently goes back to long distance dispersal with an estimated divergence time of the lineages in the Middle Miocene [11.2 (5.9–17.7) Mya]. Diversification in Melianthus appears to be much more recent than previously assumed [starting approximately 3.4 (1.9–5.2) Mya rather than approximately 8–20 Mya]. However, divergence of the Andean Hypseocharis lineage [36.9 (31.9–42.8) Mya] significantly predates the main Andean uplift: Current distributions likely go back to northward migrations and subsequent extinctions in Patagonia. Similarly, Rhynchotheca, Balbisia, and Viviania have a current southern distribution limit > 10°N of the fossil finds, indicating a massive northward displacement. The present evidence suggests that niche conservatism likely played a major role in the historical biogeography of Geraniales. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Plenasium xiei sp. nov. from the Cretaceous of Northeast China: Additional evidence for the longevity of osmundaceous ferns

A new species of the Osmundaceae, Plenasium xiei sp. nov., is herein described from the Cretaceous of Northeast China. The specimens examined here represent the earliest unequivocal record of the extant genus Plenasium in Eurasia based on fossil rhizomes. The rhizome consists of a central stem with a mantle of petiole bases and adventitious roots. The stem contains an ectophloic‐dictyoxylic siphonostele and a two‐layered cortex. The C‐shaped leaf trace bears two protoxylem bundles at the point of separation from the stele. The pith is heterogeneous. The parenchymatous inner cortex is thinner than the sclerenchymatous outer cortex. Lobed sclerenchyma bands occur at the adaxial sides of the stem xylem strands, in the concavity of the leaf trace, and along the adaxial side of the vascular bundles of the petiole base. In distal petiole portions, the sclerenchyma band splits into several groups in the transverse view. Sclerenchyma rings are heterogeneous with an abaxial sclerenchymatous arc of thick‐walled fibers. Numerous sclerenchyma strands of thick‐walled fibers appear in the petiolar inner cortex and the stipular wing. These fossils provide unambiguous evidence for the existence of subgenus Plenasium of modern Plenasium by at least the Late Cretaceous, demonstrating the longevity of this extant subgenus. Altogether the leaf and rhizome fossil records of Plenasium indicate that this genus was widely distributed across North America and Eurasia from the Early Cretaceous to the Early Cenozoic, followed by a range restriction to Eurasia in the Late Cenozoic. Extant Plenasium species are only known from East and Southeast Asia.     

Paleoenvironmental and paleobiogeographical implications of the microfossil assemblage from the Late Cretaceous intertrappean beds of the Manawar area,District Dhar,Madhya Pradesh,Central India

Abstract

An assemblage of microfossils consisting of non-marine ostracods (Cypridopsis, Gomphocythere, Zonocypris, Eucypris, and Frambocythere), charophyte gyrogonites (Platychara), molluscs (Viviparus, Valvata, and Lymnaea), and fish remains (mainly Phareodus), is here reported from a new intertrappean locality near the town of Manawar, District Dhar, Madhya Pradesh, Central India. The biotic component recovered suggests a Late Cretaceous (Maastrichtian) age for the intertrappean deposit near Manawar. Paleoenvironmentally, the overall biotic assemblage recovered indicates the presence of a freshwater palustrine/lacustrine depositional system connected to a low energy stream/river. Paleobiogeographically, the known high diversity of ostracod genera, especially Eucypris, Cypridopsis, and Gomphocythere, hints at endemism within the Indian Subcontinent during the Late Cretaceous (Maastrichtian). However, the cosmopolitan distribution of the charophyte genus Platychara in the K-Pg interval across the globe (Africa, Europe, and America) and its absence in the Upper Cretaceous of China and Mongolia is quite intriguing.     

New evidence of Ceratosaurus (Dinosauria: Theropoda) from the Late Jurassic of the Lusitanian Basin,Portugal

A theropod assigned to Ceratosaurus was previously reported from the Portuguese Lusitanian Basin based on a limited number of elements of a single individual. Here, we describe newly discovered elements that likely pertain to same, earlier described, specimen. The new elements provide additional evidence that the range of Ceratosaurus spanned from what is now North America into Europe. Previously, some differences were noted between the Portuguese specimens and the North American Ceratosaurus. We consider these differences to be trivial and attribute them to individual variation and/or ontogeny. The following set of features (lesser trochanter positioned low on the femur; crista tibiofibularis obliquely oriented with respect to the axis of the femoral shaft; infrapopliteal ridge present posteriorly on the femur; large cnemial crest; and medial condyle of the tibia continuous with proximal end) indicate that the Portuguese specimen is assignable to Ceratosaurus. This record constitutes one of the scarce evidence of basal ceratosaurian theropods in the Late Jurassic of Europe. Despite the abundance, diversity and wide geographical distribution of ceratosaurs during the Late Cretaceous, its early evolutionary history remains poorly understood. The Portuguese specimens constitute an important evidence for the knowledge of the paleobiogeographic evolution of the clade during the Late Jurassic.