The climate of the early Eocene was characterized by much higher temperatures and a smaller equator-to-pole surface temperature gradient than today. Comprehensive models have been reasonably successful in simulating that annual average. However, good simulations seasonal variations, particular warmer Arctic winters over land, proven more difficult. Further, while increased greenhouse gases seem...

A multi-million-year decrease in global temperatures during the Eocene was accompanied by large reorganisations to ocean circulation, chemistry and biological productivity. These changes culminated rapid growth of grounded ice on Antarctica Eocene–Oligocene climate transition (EOT), ?34 million years ago. However, while it is likely that environmental perturbations this magnitude altered oceani...

The first known upper dentitions--an adult and subadult--of the cercamoniine adapiform Aframonius dieides are described. Comparisons show that A. dieides has an upper molar morphology resembling that of other cercamoniine adapids but the species lacks some of their typical specializations. The new dental material confirms that Aframonius stands closer to Mahgarita from west Texas and Cercamoniu...

Ypresioneura obscura gen. et sp. nov. from the early Eocene (Ypresian) McAbee locality (Canada, British Columbia) is described. It is assigned to the extinct neuropteroid family Corydasialidae, as the second known genus and species. The Corydasialidae was previously known only from late Eocene (Priabonian) Baltic amber. It was originally assigned to the Megaloptera, but the character states tha...

The study of a new specimen of Petrolestes hendersoni from the Eocene Green Formation allows a more precise description of the enigmatic damselfly and the diagnosis of the Petrolestini. Petrolestes messelensis sp. nov. is described from the Eocene Messel Formation in Germany, extending the distribution of the Petrolestini to the European Eocene. The new damsel-dragonfly family Pseudostenolestid...

We describe a new species of homolid crab from the Ypresian (early Eocene) Roda Formation Huesca province (Aragon, Spain). In spite fragmentary condition sole specimen, some preserved frontal elements, and in particular complete left cheliped, allow inclusion it within genus Paromola Wood-Mason Alcock, 1891, based on morphological similarities with extant this genus. Direct comparison specimens...

Isotopic age determinations (40Ar/39Ar) and associated magnetic polarity stratigraphy for Casamayoran age fauna at Gran Barranca (Chubut, Argentina) indicate that the Barrancan "subage" of the Casamayoran South American Land Mammal "Age" is late Eocene, 18 to 20 million years younger than hitherto supposed. Correlations of the radioisotopically dated magnetic polarity stratigraphy at Gran Barra...

Pinnularia is an ecologically important and species-rich genus of freshwater diatoms (Bacillariophyceae) showing considerable variation in frustule morphology. Interspecific evolutionary relationships were inferred for 36 Pinnularia taxa using a five-locus dataset. A range of fossil taxa, including newly discovered Middle Eocene forms of Pinnularia, was used to calibrate a relaxed molecular clo...

A new taxon of swift-like birds is described from the Middle Eocene of Messel (Germany). It is tentatively assigned to the extinct family Jungornithidae and exhibits a completely unexpected feathering, which contrasts sharply with that of recent swifts. The short and rounded wings clearly show that it was not adapted to gliding, but might have caught its prey by sallying flights from a perch. T...