A new darwinopteran pterosaur reveals arborealism and an opposed thumb.

Pterosaurs, which lived during the Mesozoic, were the first known vertebrates to evolve powered flight. Arboreal locomotion has been proposed for some taxa, and even considered to have played a role in the origin of pterosaur flight. Even so, there is still need for comprehensive quantitative ecomorphological analyses.

Altered fluvial patterns in North China indicate rapid climate change linked to the Permian-Triassic mass extinction.

The causes of the severest crisis in the history of life around the Permian-Triassic boundary (PTB) remain controversial. Here we report that the latest Permian alluvial plains in Shanxi, North China, went through a rapid transition from meandering rivers to braided rivers and aeolian systems. Soil carbonate carbon isotope (δC), oxygen isotope (δO), and geochemical signatures of weathering intensity reveal a consistent pattern of deteriorating environments (cool, arid, and anoxic conditions) and climate fluctuations across the PTB.

A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance.

Microraptorines are a group of predatory dromaeosaurid theropod dinosaurs with aerodynamic capacity. These close relatives of birds are essential for testing hypotheses explaining the origin and early evolution of avian flight. Here we describe a new 'four-winged' microraptorine, Changyuraptor yangi, from the Early Cretaceous Jehol Biota of China.

Life history of a basal bird: morphometrics of the Early Cretaceous Confuciusornis.

Confuciusornis sanctus stands out among the remarkable diversity of Mesozoic birds recently unearthed from China. Not only is this primitive beaked pygostylian (birds with abbreviated caudal vertebrae fused into a pygostyle) much more abundant than other avian taxa of this age but differences in plumage between specimens--some having a pair of long stiff tail feathers--have been interpreted as evidence for the earliest example of sexual dimorphism in birds. We report the results of a multivariate morphometric study involving measurements of more than 100 skeletons of C.

An upper Cretaceous lizard with a lower temporal arcade.

The reduced lower temporal arcade of the skull and the movable quadrate are the most distinctive features of squamates. Up to now, no exception has been documented for any fossil or extant squamates. We report here a new fossil lizard that possesses a complete lower temporal arcade and an unmovable quadrate.

A nearly modern amphibious bird from the Early Cretaceous of northwestern China.

Three-dimensional specimens of the volant fossil bird Gansus yumenensis from the Early Cretaceous Xiagou Formation of northwestern China demonstrate that this taxon possesses advanced anatomical features previously known only in Late Cretaceous and Cenozoic ornithuran birds. Phylogenetic analysis recovers Gansus within the Ornithurae, making it the oldest known member of the clade. The Xiagou Formation preserves the oldest known ornithuromorph-dominated avian assemblage.

Palaeontology: pterosaur egg with a leathery shell.

The recent discovery of a pterosaur egg with embryonic skeleton and soft tissues from the Yixian Formation confirmed that the flying pterosaurs were oviparous. Here we describe another pterosaur egg whose exquisite preservation indicates that the shell structure was soft and leathery.