The Paleocene-Eocene Thermal Maximum (PETM) is correlated with the first occurrences of earliest modern mammals in the Northern Hemisphere. The latest Paleocene Clarkforkian North American Land Mammal Age, that has yielded rodents and carnivorans, is the only exception to this rule. However, until now no pre-PETM localities have yielded modern mammals in Europe or Asia. We report the first Clarkforkian equivalent Land Mammal Age in the latest Paleocene deposits of the basal Sparnacian facies at Rivecourt, in the north-central part of the Paris Basin. The new terrestrial vertebrate and macroflora assemblages are analyzed through a multidisciplinary study including sedimentologic, stratigraphic, isotopic, and palynological aspects in order to reconstruct the paleoenvironment and to evaluate biochronologic and paleogeographic implications. The mammals are moderately diverse and not abundant, contrary to turtles and champsosaurs. The macroflora is exceptional in preservation and diversity with numerous angiosperms represented by flowers, fruits, seeds and wood preserved as lignite material, revealing an abundance of Arecaceae, Betulaceae, Icacinaceae, Menispermaceae, Vitaceae and probably Cornaceae. Results indicate a Late Paleocene age based on carbon isotope data, palynology and vertebrate occurrences such as the choristoderan Champsosaurus, the arctocyonid Arctocyon, and the plesiadapid Plesiadapis tricuspidens. However, several mammal species compare better with the earliest Eocene. Among these, the particular louisinid Teilhardimys musculus, also recorded from the latest Paleocene of the Spanish Pyrenees, suggests a younger age than the typical MP6 reference level. Nevertheless, the most important aspect of the Rivecourt fauna is the presence of dental remains of a rodent and a “miacid” carnivoran, attesting to the presence of two modern mammalian orders in the latest Paleocene of Europe. Interestingly, these two groups are also the only modern groups recorded from the latest Paleocene of North America, making Rivecourt the first direct equivalent to the Clarkforkian Land Mammal Age outside of North America.

This article presents new biostratigraphic dating, facies analysis, organic geochemical data and Nd-Sr isotopic provenance from five outcrops of southern Amazonia to document for the first time the presence of a shallow marine ingression in the Paleocene of southern Amazonia basin. The co-occurrence of a selachian assemblage encompassing Potobatis sp., Ouledia sp., and Pristidae indet. with the ostracod Protobuntonia sp. and the charophytes Peckichara cf. varians meridionalis, Platychara perlata, and Feistiella cf. gildemeisteri suggests a Paleocene age for the studied deposits (most likely Thanetian but potentially Danian). Fifteen facies have been recognized and have been grouped into three facies assemblages. Facies association A corresponds to the sedimentary filling of a tide-influenced meandering channel formed in the fluvialtidal transition zone. Facies association B is related to more distal tidal-flats, little channelized tidal inlets and saltmarshes deposits. Facies association C corresponds to a stressed shallow marine environment such as a bay or a lagoon. The δ13CTOC value (-23.4 ‰) of MD-184 is enriched in 13C compared to the other samples suggesting the presence of substantial amounts of marine organic matter in MD-184. The δ13CTOC values of samples from other outcrops (-27.3 to -29.8 ‰) indicate a mixed organic matter origin, from terrestrial to brackish environments. The analyzed sediments have similar Nd-Sr isotopic compositions as those of the Cenozoic sediments of the Altiplano (εNd(0) values from -6.2 to -10.7 and 87Sr/86Sr compositions from 0.712024 to 0.719026) indicating a similar volcanic source. This multidisciplinary dataset documents the presence of a tide-dominated estuary sourced by the proto Western Cordillera debouching into a shallow marine bay during Paleocene times. This transgression might be explained by subsidence created in response to the proto-Western Cordillera loading. Similar to Miocene marine incursions affecting the Pebas megawetland, Paleogene marine incursions in the Amazonian foreland basin associated with Andean uplift may have played a role in the Neotropical biodiversity dynamics in favouring biogeographical isolation and promoting allopatric speciation for terrestrial organisms. Highlights:The presence of agglutinated benthic foraminifer Karreriella conversa, ostracod Protobuntonia and charophyte Peckichara cf. varians meridionalis suggest a Paleogene age for the studied deposits.We define three facies associations related to a tide-dominated estuary debouching into a shallow-marine bay or lagoon.

contexte géologique et détail biostratigraphique des formations cénozoïques à partir des assemblages de vertébrés fossiles.

Gagnaison C. 2013. -Les assemblages de vertébrés dans deux sites paléontologiques du bassin miocène de Savigné-sur-Lathan/Noyant-sous-le-Lude : La Guimardière et Pelmer (Maine-et-Loire, France).

A detailed report of the decapod crustaceans discovered in the Middle-Late Miocene outcrops of the 'Faluns' of Anjou-Touraine (West of France) is here presented. The Couffon's compendium (1908) is reviewed, and the systematics updated. A total of seven genera and eight species of eubrachyuran crabs, undetermined chelae, and one anomuran species, are reported. The varied decapod assemblage, dominated by Pilumnus mediterraneus (Lőrenthey, 1897), shows clear affinity with coeval decapod faunas from the Mediterranean and Paratethys realm. This fauna dwelt in a shallow warm and agitated environment of bryozoan meadows. The age of Hebertides jurassica Guinot, De Angeli & Garassino, 2007, is confirmed, and the probable provenance of the holotype is suggested. We also discuss the generic status of Scylla michelini A. Milne-Edwards, 1861 transferred herein to Necronectes A. Milne-Edwards, 1881. RÉSUMÉ Évaluation des crustacés décapodes fossiles du Miocène moyen-supérieur des 'Faluns' (Anjou-Touraine, France). Une présentation détaillée d'une série de crustacés décapodes provenant de différents affleurements des faluns du Miocène moyen-supérieur de l'Anjou-Touraine (ouest de la France) est présentée dans cet article. Un total de sept genres et huit espèces d'eubrachyures et une espèce d'anomure sont décrits ici. Cet assemblage de décapodes est varié, dominé par Pilumnus mediterraneus (Lőrenthey, 1897), montrant une affinité claire avec les faunes de décapodes contemporaines de la Mer Méditerranée et du domaine paratéthysien. Cette faune vivait dans un environnement peu profond, chaud et agité, dans des prairies à bryozoaires. L'âge de Hebertides jurassica Guinot, De Angeli & Garassino, 2007 est confirmé, et la provenance éventuelle de l'holotype est ici suggérée. Le statut générique de Scylla michelini A. Milne-Edwards, 1861 est discuté et transféré à Necronectes A. Milne-Edwards, 1881.