scholarly journals Taxonomic Composition and Trophic Structure of the Continental Bony Fish Assemblage from the Early Late Cretaceous of Southeastern Morocco

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0125786 ◽  
Author(s):  
Lionel Cavin ◽  
Larbi Boudad ◽  
Haiyan Tong ◽  
Emilie Läng ◽  
Jérôme Tabouelle ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Fish Assemblage ◽  
Trophic Structure ◽  
Taxonomic Composition ◽  
Bony Fish ◽  
Early Late

scholarly journals An overview of the pterosaur assemblage from the Cambridge Greensand (Cretaceous) of Eastern England

Fossil Record ◽  
2001 ◽  
Vol 4 (1) ◽  
pp. 189-221 ◽  
Author(s):  
D. M. Unwin
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Single Species ◽  
Taxonomic Composition ◽  
Valid Species ◽  
Ecological Differentiation ◽  
Systematic Revision ◽  
Considerable Confusion ◽  
Disjunct Populations ◽  
Early Late

The Cambridge Greensand, a remanié deposit that crops out in Cambridgeshire, eastern England, has yielded numerous, though fragmentary, late Early Cretaceous (Albian) vertebrate fossils including more than 2000 isolated pterosaur bones. So far, 32 species of pterosaur have been proposed in connection with the Cambridge Greensand material, but there has been and continues to be considerable confusion concerning the validity of these taxa, their relationships to each other and to other pterosaurs, and the material upon which they were established. A comprehensive systematic revision identified eleven valid species distributed among three families: the Ornithocheiridae (<i>Ornithocheirus simus</i> and possibly a second, as yet unnamed species of <i>Ornithocheirus, Coloborhynchus capito, Coloborhynchus sedgwickii, Anhanguera cuvieri</i>, and <i>Anhanguera fittoni</i>); the Lonchodectidae (<i>Lonchodectes compressirostris, Lonchodectes machaerorhynchus, Lonchodectes microdon</i> and <i>Lonchodectes platystomus</i>); and a species of edentulous pterosaur (<i>Ornithostoma sedgwicki</i>) that may represent the earliest record for the Pteranodontidae. It is possible that some of the taxa currently recognised represent sexual dimorphs (<i>Coloborhynchus capito</i> and <i>Coloborhynchus sedgwickii, Lonchodectes compressirostris</i> and <i>Lonchodectes machaerorhynchus</i>), or disjunct populations of a single species (<i>Ornithocheirus simus</i> and <i>Ornithocheirus</i> sp., <i>Lonchodectes compressirostris</i> and <i>Lonchodectes microdon</i>) and that there may be as few as seven valid species, but the Cambridge Greensand pterosaurs are too poorly known to demonstrate this at present. The Cambridge Greensand pterosaur assemblage is similar to a slightly younger, but much smaller assemblage from the Lower Chalk of England and shares some elements, such as ornithocheirids, in common with many other late Early and early Late Cretaceous assemblages. It is distinguished by the absence of tapejarids and the presence of <i>Lonchodectes</i> which, so far, is only known from the Cretaceous of England. The disparity in taxonomic composition is possibly related to ecological differentiation, and might also reflect some provincialism in late Early and early Late Cretaceous pterosaur faunas. <br><br> Der Cambridge Greensand, eine in Ostengland aufgeschlossene Remanié-Ablagerung, hat zahlreiche Wirbeltiere aus der oberen Unterkreide (Alb) geliefert. Darunter fanden sich mehr als 2000 isolierte Pterosaurierknochen. Insgesamt wurden aus dem Greensand bis zu 32 Flugsauriertaxa beschrieben, was zu einer beträchtlichen taxonomischen und nomenklatorischen Verwirrung geführt hat, die bis heute andauert. Eine vollständige Revision erkennt 11 Arten aus drei Familien an: (1) die Ornithocheiridae (<i>Ornithocheirus simus</i> und vielleicht eine zweite, bislang unbenannte Art von <i>Ornithocheirus</i>, sowie <i>Coloborhynchus capito, Coloborhynchus sedgwickii, Anhanguera cuvieri</i> und <i>Anhanguera fittoni</i>); (2) die Lonchodectidae (<i>Lonchodectes compressirostris, Lonchodectes machaerorhynchus, Lonchodectes microdon</i> und <i>Lonchodectes platystomus</i>); und schließlich einen zahnlosen Flugsaurier (<i>Ornithostoma sedgwicki</i>). der zu keiner der vorgenannten Familien gehört und sich als stratigraphisch ältester Nachweis der Pteranodontidae erweisen könnte. Es ist nicht auszuschließen, dass einige der gegenwärtig erkannten Taxa eher einen ausgeprägten Sexualdimorphismus illustrieren denn taxonomisch distinkte Arten darstellen (<i>Coloborhynchus capito</i> und <i>Coloborhynchus sedgwickii</i>, <i>Lonchodectes compressirostris</i> und <i>Lonchodectes machaerorhynchus</i>) oder sogar lediglich Endpunkte einer intraspezifisch variablen Population (<i>Ornithocheirus simus</i> und <i>Ornithocheirus</i> sp., <i>Lonchodectes compressirostris</i> und <i>Lonchodectes microdon</i>). In dieser strengeren Fassung bestünden nur sieben gültige Arten, doch leider sind die Flugsaurier des Cambridge Greensand zu schlecht bekannt, um diese Fragen zu beantworten. Die Flugsaurierfauna des Cambridge Greensand ähnelt jüngeren kreidezeitlichen Faunen aus dem Lower Chalk von England. Weiter-hin enthält sie Faunenelemente, wie etwa Ornithocheiriden. die auch für zahlreiche andere Faunen der hohen Unterkreide und tiefen Oberkreide charakteristisch sind. Das Fehlen von Tapejariden und das Auftreten des anscheinend endemischen <i>Lonchodectes</i> sind weitere Kennzeichen des Cambridge Greensand. Die Zusammensetzung der Pterosaurierfaunen folgte offenbar ökologischen Differenzierungen und illustriert einen gewissen Provinzialismus an der Grenze Unter-Oberkreide. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20010040112" target="_blank">10.1002/mmng.20010040112</a>

scholarly journals Isolated pliosaurid teeth from the Albian–Cenomanian (Cretaceous) of Annopol, Poland

2017 ◽  
Vol 67 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Daniel Madzia ◽  
Marcin Machalski
Keyword(s):  
Cross Section ◽  
Late Cretaceous ◽  
Type Species ◽  
Late Jurassic ◽  
Morphological Variability ◽  
Original Material ◽  
Tooth Crown ◽  
Similar Morphology ◽  
Faunal Turnover ◽  
Early Late

AbstractBrachauchenine pliosaurids were a cosmopolitan clade of macropredatory plesiosaurs that are considered to represent the only pliosaurid lineage that survived the faunal turnover of marine amniotes during the Jurassic- Cretaceous transition. However, the European record of the Early to early Late Cretaceous brachauchenines is largely limited to isolated tooth crowns, most of which have been attributed to the classic Cretaceous taxon Polyptychodon. Nevertheless, the original material of P. interruptus, the type species of Polyptychodon, was recently reappraised and found undiagnostic. Here, we describe a collection of twelve pliosaurid teeth from the upper Albian-middle Cenomanian interval of the condensed, phosphorite-bearing Cretaceous succession at Annopol, Poland. Eleven of the studied tooth crowns, from the Albian and Cenomanian strata, fall within the range of the morphological variability observed in the original material of P. interruptus from the Cretaceous of England. One tooth crown from the middle Cenomanian is characterized by a gently subtrihedral cross-section. Similar morphology has so far been described only for pliosaurid teeth from the Late Jurassic and Early Cretaceous. Even though it remains impossible to precisely settle the taxonomic distinctions, the studied material is considered to be taxonomically heterogeneous.

scholarly journals Depositional setting and limiting factors of early Late Cretaceous glaucony formation: implications from Cenomanian glauconitic strata (Elbtal Group, Germany)

Facies ◽  
2021 ◽  
Vol 67 (3) ◽  
Author(s):  
Markus Wilmsen ◽  
Udita Bansal
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Time Scales ◽  
Late Cretaceous ◽  
Limiting Factors ◽  
High Accumulation ◽  
Spatio Temporal ◽  
Facies Types ◽  
Facies Succession ◽  
Early Late

AbstractCenomanian strata of the Elbtal Group (Saxony, eastern Germany) reflect a major global sea-level rise and contain, in certain intervals, a green authigenic clay mineral in abundance. Based on the integrated study of five new core sections, the environmental background and spatio-temporal patterns of these glauconitic strata are reconstructed and some general preconditions allegedly needed for glaucony formation are critically questioned. XRD analyses of green grains extracted from selected samples confirm their glauconitic mineralogy. Based on field observations as well as on the careful evaluation of litho- and microfacies, 12 glauconitc facies types (GFTs), broadly reflecting a proximal–distal gradient, have been identified, containing granular and matrix glaucony of exclusively intrasequential origin. When observed in stratigraphic succession, GFT-1 to GFT-12 commonly occur superimposed in transgressive cycles starting with the glauconitic basal conglomerates, followed up-section by glauconitic sandstones, sandy glauconitites, fine-grained, bioturbated, argillaceous and/or marly glauconitic sandstones; glauconitic argillaceous marls, glauconitic marlstones, and glauconitic calcareous nodules continue the retrogradational fining-upward trend. The vertical facies succession with upwards decreasing glaucony content demonstrates that the center of production and deposition of glaucony in the Cenomanian of Saxony was the nearshore zone. This time-transgressive glaucony depocenter tracks the regional onlap patterns of the Elbtal Group, shifting southeastwards during the Cenomanian 2nd-order sea-level rise. The substantial development of glaucony in the thick (60 m) uppermost Cenomanian Pennrich Formation, reflecting a tidal, shallow-marine, nearshore siliciclastic depositional system and temporally corresponding to only ~ 400 kyr, shows that glaucony formation occurred under wet, warm-temperate conditions, high accumulation rates and on rather short-term time scales. Our new integrated data thus indicate that environmental factors such as great water depth, cool temperatures, long time scales, and sediment starvation had no impact on early Late Cretaceous glaucony formation in Saxony, suggesting that the determining factors of ancient glaucony may be fundamentally different from recent conditions and revealing certain limitations of the uniformitarian approach.

Radiolarian assemblages of Middle and Late Jurassic to early Late Cretaceous (Cenomanian) ages from an olistolith record pelagic deposition within the Bornova Flysch Zone in western Turkey

2012 ◽  
Vol 183 (4) ◽  
pp. 307-318 ◽  
Author(s):  
Ugur Kagan Tekin ◽  
M. Cemal Göncüoglu ◽  
Seda Uzuncimen
Keyword(s):  
Late Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
Western Turkey ◽  
Oceanic Basin ◽  
Platform Margin ◽  
Lowermost Part ◽  
Early Late ◽  
Radiolarian Assemblages

Abstract The Bornova Flysch Zone (BFZ) in NW Anatolia comprises several olistoliths or tectonic slivers, representing various parts of the Izmir-Ankara ocean. Radiolarian assemblages extracted from one of the olistoliths of the BFZ, cropping out along the Sögütlü section, to the NE Manisa city, were studied in detail. The lowermost part of the section contains latest Bajocian – early Callovian radiolarian taxa, followed by radiolarian assemblages indicating Late Jurassic to early Late Cretaceous (Cenomanian) ages. Previous studies reveal that the Izmir-Ankara oceanic basin was initially opened during late Ladinian – early Carnian. The new radiolarian data obtained from this olistolith reveals that relatively condensed, and possibly more or less continuous, pelagic sedimentation took place during the late Middle Jurassic to early Late Cretaceous in a non-volcanic oceanic basin closer to the Tauride-Anatolide platform margin.

An early Late Cretaceous (Cenomanian) sturgeon (Acipenseriformes) from the Dunvegan Formation, northwestern Alberta, Canada

2014 ◽  
Vol 51 (7) ◽  
pp. 677-681 ◽  
Author(s):  
Matthew J. Vavrek ◽  
Alison M. Murray ◽  
Phil R. Bell
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Recent Survey ◽  
Peace River ◽  
Northern Regions ◽  
Early Late

A recent survey of the middle Cenomanian Dunvegan Formation along the Peace River, Alberta, has yielded a partial skull of a large acipenseriform fish. The fossil was from an animal approximately 5 m in length, based on comparisons with living relatives. Though incomplete, this represents an important record of mid-Cretaceous fish from northern North America, as formations of this age are virtually unexplored in northern regions. This fossil is the oldest acipenserid from North America, and one of the most northerly known.

Vertebrate assemblages from the early Late Cretaceous of southeastern Morocco: An overview

2010 ◽  
Vol 57 (5) ◽  
pp. 391-412 ◽  
Author(s):  
L. Cavin ◽  
H. Tong ◽  
L. Boudad ◽  
C. Meister ◽  
A. Piuz ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Early Late

Maastrichtian representatives of the dragonfly family Aeschnidiidae question the entomofaunal turnover of the early Late Cretaceous

2021 ◽  
Vol 4 (3) ◽  
Author(s):  
ANDRÉ NEL
Keyword(s):  
Late Cretaceous ◽  
Aquatic Insects ◽  
Fossil Record ◽  
Current Knowledge ◽  
Alternative Scenario ◽  
Family Level ◽  
Early Late ◽  
Freshwater Environments

Gaps in the fossil record are the major challenge for estimations of impacts of crises of biodiversity of the various clades. They can lead to important misinterpretations in the effects of the different events on the fauna and flora. It is especially the case for the end-Cretaceous, which is ‘near the midpoint of a 16-million-year gap in the insect fossil record’ (Schachat & Labandeira, 2021: 111). All the important Cretaceous insect Konzentrat Lagerstätten are before the Turonian. The analysis of Schachat et al. (2019) has reconstructed a massive loss of family-level diversity for the insects at the boundary Cretaceous-Cenozoic, a possible artefact due to this gap. An alternative scenario was that a turnover in the entomofauna occurred during the early Late Cretaceous in relation to the floristic changes of the Albian–Cenomanian (Nel et al., 2018). This turnover would have also affected the aquatic insects through important changes in the freshwater environments (Sinitshenkova & Zherikhin, 1996; Ivanov & Sukatsheva, 2002). The current knowledge on the odonatan fossil record suggests a pronounced turnover with the last records of several major clades during the Cenomanian-Turonian and first records of several modern ones during the same period (Nel et al., 2015). The widespread and very diverse Jurassic-Cretaceous family Aeschnidiidae is among the best examples of such extinctions supposed to have occurred after the Cenomanian, because of the absence of any fossil in younger strata.

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