The global Triassic timescale based on tetrapod biochronology remains a robust tool for both global and regional age assignment and correlation. The Lootsbergian and Nonesian land-vertebrate faunachrons (LVFs) are of Early Triassic age; cross correlation of part of the Lootsbergian to the Olenekian and all or part of the Nonesian to the Anisian lacks support. In the South African Karoo basin, b...

We present a new crustal cross section through the east-west trending ultrahigh-pressure (UHP) Dabie Shan orogenic belt, east central China, based on a 400km-long seismic refraction profile. Data from our profile reveal that the cratonal blocks north and south of the orogen are composed of 35-km-thick crust consisting of three layers (upper, middle, and lower crust) with average seismic velocit...

We welcome the examination by Marshall (1) of our study (2), particularly his corrected statistical analysis of confidence intervals on stratigraphic ranges, which we accept. We believe, however, that in the process he has misinterpreted both our original data and his own reanalysis. We argued for both gradual and abrupt aspects to the Permian-Triassic (P-T) extinction, whereas Marshall suggest...

The Permian ended with the largest of known mass extinctions in the history of life. This signal event has been difficult to recognize in Antarctic non-marine rocks, because the boundary with the Triassic is defined by marine fossils at a stratotype section in China. Late Permian leaves (Glossopteris) and roots Vertebraria), and Early Triassic leaves (Dicroidium) and vertebrates (Lystrosaurus) ...

Variation in the geographic spread of fossil localities strongly biases inferences about the evolution of biodiversity, due to the ubiquitous scaling of species richness with area. This obscures answers to key questions, such as how tetrapods attained their tremendous extant diversity. Here, we address this problem by applying sampling standardization methods to spatial regions of equal size, w...

The coupled evolution of land plants, CO2, and climate over the last half billion years has maintained atmospheric CO2 concentrations within finite limits, indicating the involvement of a complex network of geophysiological feedbacks. But insight into this important regulatory network is extremely limited. Here we present a systems analysis of the physiological and geochemical processes involve...

The rise of dinosaurs was a major event in vertebrate history, but the timing of the origin and early diversification of the group remain poorly constrained. Here, we describe Nyasasaurus parringtoni gen. et sp. nov., which is identified as either the earliest known member of, or the sister-taxon to, Dinosauria. Nyasasaurus possesses a unique combination of dinosaur character states and an elev...

the permian-triassic boundary in the himalayas is reviewed and discussed in the light of palaeontologic and stratigraphic data collected during the past two and a half decades from kashmir, spiti and nepal. the deposition of the kuling shales and their equivalents in different parts of the himalayas was followed by shallowing and regression of the sea. sedimentation was interrupted at the top o...