2 nouveaux articles sur la Charente
Cenomanian paralic deposits of Charentes (southwestern France)have yielded abundant vertebrate microremains, including rather diversifiedcontinental taxa (e.g., frogs, turtles, crocodilians, dinosaurs, pterosaurs,lizards, and mammals). In this preliminary report, the succession of faunalassemblages observed is briefly described in relation to palaeoenvironmentalchange resulting from the Cenomanian-early Turonian transgressive episode.Continental forms occur commonly in estuarine and shallow marine rocks ofthe lower part of the Cenomanian stage, but seem to be lacking in youngerstrata deposited in more open marine settings. Among an unexpectedbiodiversity, several non-marine groups (e.g., ziphodont crocodilians,carcharodontosaurid and troodontid dinosaurs, marsupial-like mammals) arerecorded for the first time in the lower Upper Cretaceous of Europe, thusproviding new palaeobiogeographical indications for this poorly documentedpart of the world.
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Didier Néraudeau, Vincent Perrichot, Jean-Paul Colin, Vincent Girard, Bernard Gomez, François Guillocheau, Edwige Masure, Daniel Peyrot, Florent Tostain, Blaise Videt, Romain Vullo, 2008. A new amber deposit from the Cretaceous (uppermost Albian-lowermost Cenomanian) of southwestern France. Cretaceous Research
A Cretaceous amber deposit has recently been discovered in a quarry of Charente-Maritime (southwestern France), at Cadeuil. This paper presents the sedimentary and palaeoenvironmental settings of the uppermost Albian-lowermost Cenomanian series including the amber deposit. A preliminary analysis of the amber samples reveals diverse fossil arthropods (a few mites and at least 20 insect families within 9 orders), as well as numerous micro-organisms, mainly algae and mycelia. A myceloid colony of bacteria, a flagellate algae and four especially well preserved insects are illustrated (Diptera Dolichopodidae, Diptera Chironomidae, Hymenoptera Parasitica, and Heteroptera Tingidae). The abundance of the limnitic micro-organisms is discussed in terms of bloom events. Their relative scarcity in almost all the amber pieces containing fossil arthropods is attributed to differences in the origin of resin: production along trunk and branches for amber with arthropods; production by aquatic roots for amber rich in algae. The absence of pollen and spores in amber is attributed to differences in the respective periods of resin and palynomorph production, which may be related to a seasonal climate during the Albian-Cenomanian transition in Western Europe.
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