The first Triassic dipteran from South America is described based on an isolated wing from the lower Upper Triassic deposits of Argentina (Mendoza Province, Potrerillos Formation, Quebrada del Durazno locality). Trihennigma zavattierii gen. et sp. nov. is a member of the Mesozoic family Hennigmatidae, previously recorded only from Eurasia. A key for the genera and species of Hennigmatidae is pr...

The first Lower Jurassic (Lias) spider is described as Seppo koponeni n. gen. & n. sp. from a single female specimen from Grimmen, Germany. It most likely belongs to the Palpimanoidea, on account of the presence of cheliceral peg teeth and other features consistent with palpimanoid families, though its familial placement is uncertain. Its presence in the region at that time concurs with ideas a...

BACKGROUND The evolutionary history of Mesozoic terrestrial vertebrates from the Arabian Peninsula is virtually unknown. Despite vast exposures of rocky outcrops, only a handful of fossils have yet been described from the region. Here we report a multi-taxon dinosaur track assemblage near Madar village, 47 km north of Sana'a, Republic of Yemen. This represents the first dinosaur tracksite from ...

An analysis of 68 floras from the Pennsylvanian and Early Permian of Euramerica reveals distinct patterns of environmental distribution. Wetland assemblages are the most commonly encountered floras from the Early and Middle Pennsylvanian. Floras from drier habitats characterize the Permian. Both wetland and dry-site floras occur in the Late Pennsylvanian, but floristic overlap is minimal, which...

1. Sauropod dinosaurs were the largest terrestrial animals ever, and the combination of selective pressures that might have lead to such extraordinary sizes has long been discussed. 2. Here, we argue that a previous suggestion that large size may be a response to unusually high C/N ratios in available plant foods has been prematurely discarded. C/N ratios were likely to be high during much of t...

Fossil leaves assigned to the genus Ginkgo are increasingly being used to reconstruct Mesozoic and Tertiary environments based on their stomatal and carbon isotopic characteristics. We sought to provide a more secure basis for understanding variations seen in the plant fossil record by determining the natural variability of these properties of sun and shade leaf morphotypes of Ginkgo biloba tre...