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The genus Chloephaga Eyton, 1838, consisting of four species that breed in Patagonia, encompasses anatids endemic to South America. Despite their prominence in the present-day avifauna, these species have left behind a limited fossil record. The aim of the present contribution is to describe Chloephaga fossils coming from Middle Pleistocene levels (San José Sequence) cropping out at Bajo San José site, southwestern Buenos Aires Province, Argentina. The specimens are referred to three different taxa, including a new species, Chloephaga dabbenei n. sp., a smaller but indeterminate taxon, which is also probably a new species, and the extant species C. picta (J.F.Gmelin, 1789). The newly described species is notably large, falling within the upper size range observed in males of C. picta. The tarsometatarsus is straight-shafted with poorly divergent distal trochleae, features that are correlated with cursorial habits, that are absent in other members of Chloephaga. The co-occurrence of three species of the genus Chloephaga is registered nowadays in the Argentine Patagonia and in the southeast of Buenos Aires Province, when they migrate during the winter season. [ABSTRACT FROM AUTHOR]

Aim: Body size evolution has long been hypothesized to have been driven by factors linked to climate change, but the specific mechanisms are difficult to disentangle due to the wide range of functional traits that covary with body size. In this study, we investigated the impact of regional habitat changes as a potential indirect effect of climate change on body size evolution. Location: Europe and North America. Time period: The Neogene (~23–2 million years ago). Major taxa: Five orders of terrestrial mammals: Artiodactyla, Carnivora, Perissodactyla, Proboscidea and Primates. Methods: We compared the two continental faunas, which have exceptional fossil records of terrestrial mammals and underwent different processes of habitat transition during the Neogene. Using Bayesian multilevel regression models, we assessed the variation in the temporal dynamics of body size diversity among ecographic groups, defined by their continent of occurrence and dietary preference. Results: Model comparisons unanimously supported a combined effect of diet and continent on all metrics of body size frequency distributions, rejecting the shared energetic advantage of larger bodies in colder climates as a dominant mechanism of body size evolution. Rather, the diet‐specific dynamics on each continent pinpointed an indirect effect of climate change – change in habitat availability, and thus the resource landscape as a key driver of mammalian evolution. Main conclusions: Our study highlights dietary preference as a mechanistic link between mammalian evolution and habitat transition mediating an indirect climate‐change effect and demonstrates the complexity of climatic influence on biodiversity. Our findings suggest that the intensified habitat modification today likely poses a bigger threat than climate change in itself to living mammals, and perhaps all endotherms. [ABSTRACT FROM AUTHOR]

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Pterophyllum, an extinct plant of Bennettitales, constitutes a significant component of the Mesozoic flora. In this study, we identified four fossil species of Pterophyllum from the Middle Jurassic Yaojie Formation in the Yaojie Basin and the Baojishan Basin in Gansu Province, Northwest China. Through analysis of macroscopic and macroscopic characteristics, these specimens were identified as Pterophyllum xinjiangensis Zhao, P. subaequale Hartz, P. ptilum Harris, and P. angustum (Braun) Gothan. These findings bridge gaps in the study of Bennettitales fossils in the region, affirming the warm and humid climate of the Yaojie Basin and the Baojishan Basin during the Middle Jurassic. Moreover, a comprehensive analysis of 598 reported Pterophyllum fossil records in China revealed that their occurrences from the Late Triassic to the Early Cretaceous was constrained by ancient climates and tectonic. The Late Triassic exhibited the highest diversity, with 83 species, which were widespread across warm-humid and tropical-subtropical zones in China; however, their diversity decreased sharply in subsequent periods, increased slightly in the Early Cretaceous, and then disappeared. In this paper, we further examined the habitat characteristics of this genera based on its spatiotemporal distribution and the paleogeographic and paleotectonic features of its origins, elucidating the coupled relationship between its distribution and ancient geographic and tectonic factors. • Four species of Pterophyllum in Yaojie Formation are described. • 598 records of 157 species of Pterophyllum reported in China are provided. • Distribution of Pterophyllum during the Mesozoic in China is provided. • Most of the occurrences of Pterophyllum represent warm and humid climate types. • Restricted conditions of Pterophyllum distribution & evolution are discussed. [ABSTRACT FROM AUTHOR]

The Ordovician fossil record provides evidence of the most rapid, long sustained burst of biotic diversification in the history of marine life on Earth (The Great Ordovician Biodiversification Event, Webby et alii, 2004). Radiation events during Early and Middle Ordovician times caused the tripling of marine biodiversity and the establishment of Palaeozoic and Mesozoic evolutionary faunas which have the greater relevance to present-day biotic communities. Throughout the Ordovician, great ecological changes were associated with intense tectonic and volcanic activity and major reorganization of the plate-tectonic global assembly.

A set of 14 abstracts and short papers (extended abstracts) of presentations given at a meeting organized by the NFSR Working Group, "Micropaléontologie végétale et Palynologie (MVP)", held on May 11, 2005 at the University of Liège, Belgium.