A new locality of early Late Triassic age in the Richmond basin of east-central Virginia has yielded abundant remains of a diversified assemblage of small to medium-sized tetrapods that closely resembles Southern Hemisphere (Gondwanan) assemblages in the predominance of certain synapsids. Associated palynomorphs indicate an early middle Carnian age for the fossiliferous strata. The discovery su...

Recent collecting of vertebrate fossils in Petrifi ed Forest National Park as the result of an ongoing inventory of fossil localities has produced numerous important new specimens. These include phytosaur skulls and partial skeletons, aetosaur partial skeletons and isolated, but complete, osteoderms, as well as new dinosaur material that contributes new information to a currently poor dinosaur ...

Upper Triassic rocks in northwestern Argentina preserve the most complete record of dinosaurs before their rise to dominance in the Early Jurassic. Here, we describe a previously unidentified basal theropod, reassess its contemporary Eoraptor as a basal sauropodomorph, divide the faunal record of the Ischigualasto Formation with biozones, and bracket the formation with (40)Ar/(39)Ar ages. Some ...

The Permian-Triassic boundary records the most severe mass extinctions in Earth's history. Siberian flood volcanism, the most profuse known such subaerial event, produced 2 million to 3 million cubic kilometers of volcanic ejecta in approximately 1 million years or less. Analysis of (40)Ar/(39)Ar data from two tuffs in southern China yielded a date of 250.0 +/- 0.2 million years ago for the Per...

We use a method based on a statistical geomagnetic field model to recognize and correct for inclination error in sedimentary rocks from early Mesozoic rift basins in North America, Greenland, and Europe. The congruence of the corrected sedimentary results and independent data from igneous rocks on a regional scale indicates that a geocentric axial dipole field operated in the Late Triassic. The...

the sorkh shale formation (lower triassic) crops out in parts of tabas block. this formation is composed of limestone, dolomite, sandstone, shale and gypsum. its lower contact with the permian rocks and its upper contact with the shotori formation is marked by distinct erosional unconformity. to determine the depositional environments of the sorkh shale formation, stratigraphic sections of goda...

Tong, Jinnan, and Douglas H. Erwin. Triassic Gastropods of the Southern Qinling Mountains, China. Smithsonian Contributions to Paleobiology, number 92,47 pages, 11 figures, 6 plates, 5 tables, 2001. Forty-eight species in 27 genera of gastropods, including 14 new species and one new genus, are described from earlyto middle-Triassic (Scythianto Ladinian-aged) rocks from the southern Qinling Moun...

Four supergiant and numerous giant gasfields have been discovered in the Southwest Iran which produce from Permian-Triassic carbonates belong to the upper member of Dalan Formation and Kangan Formation. In this research a detailed biostratigraphic, microfacies and sequence stratigraphic study of the late Middle Permian to Triassic successions was undertaken from 850 thin sections prepared from ...

The study area is situated in the Middle part of the Tabas Block. It contains outcrops of rocks that formed along longitudinal faults in Early Cimmerian orogenic phase. The basin subsided along these faults from the Late Triassic to Early Cretaceous, which include two sedimentary cycles. A sedimentary cycle, related to Upper Triassic to Bajocian is known as Shemshak group. Another sedimentary c...