The origin of the limbless caecilians remains a lasting question in vertebrate evolution. Molecular phylogenies and morphology support that caecilians are the sister taxon of batrachians (frogs and salamanders), from which they diverged no later than the early Permian. Although recent efforts have discovered new, early members of the batrachian lineage, the record of pre-Cretaceous caecilians i...

The identification of the factors triggering continental environmental changes at Permian–Triassic transition is general interest as they allow a better understanding most controversial mass extinction Phanerozoic. This study investigates response to external forcings on successions south-east-margin Central European Basin System in Germany. Studies from this area are scarce, and its evolution ...

Abstract A transgression of the Tethys Ocean occurred in east central Iran, like other areas Ocean, around Yakhtashian/Bolorian (regional chronostratigraphical units corresponding with Artinskian/Kungurian Early Permian) transition. This led to development a carbonate platform that is represented Shirgesht area on northern part Tabas Block by Bagh-e-Vang Formation, which constitutes only known ...

Developed on the North China Craton, intracratonic Ordos Basin contains a complete Paleozoic-to-Cenozoic sediment record, allowing for long-term paleoenvironmental and climate change investigation. During Carboniferous–Permian period, convergence between block paleo-Yangtze plate to south resulted in general marine regression characterized by series of second-order transgression/regression cycl...

The d18O values of pedogenic calcites, phyllosilicates, and iron (oxyhydr)oxides from fossil soils throughout the southwestern United States show systematic paleolatitudinal and temporal trends that indicate a significant change in soil moisture conditions and atmospheric circulation patterns over southwestern Euramerica throughout latest Pennsylvanian and Early Permian time. A progressive depl...

The biotic recovery from Earth's most severe extinction event at the Permian-Triassic boundary largely reestablished the preextinction structure of marine trophic networks, with marine reptiles assuming the predator roles. However, the highest trophic level of today's marine ecosystems, i.e., macropredatory tetrapods that forage on prey of similar size to their own, was thus far lacking in the ...

A recent description and analysis of an imprint fossil from the Carboniferous concluded that it was made by a mayfly landing in sediment at the edge of water. Here, I reanalyze that trace fossil and supply experimental evidence regarding wing traces and behavior. The thorax of the trace maker lacked structures characteristic of mayflies, but closely matches a modern neopteran insect family (Tae...

This research work introduces the Early Triassic, Late Triassic-Early Jurassic, and Early Cretaceous silica-rich sand levels at east and central Alborz, Kopeh-Dagh, and Central Iran, and compares them with the Permian silica-rich sand level in the Chirouk mine at east Iran. Ghoznavi and Gheshlaq loose sand in Alborz (Early Triassic-Early Jurassic), Soh quartzite in Central Iran (Early Triassic...

The hypotheses about the origin of the primitive amniotic tarsus are very speculative. Early studies argued that the origin of the astragalus, one of the largest proximal bones in the tarsus of basal amniotes, was produced by either the fusion of two, three, or even four of the original tarsal bones, the intermedium, the tibiale and the proximal centralia (c4 and c3), or that the intermedium al...

Recently several investigators (1-5) have discussed the immigration of the primitive mammals (monotremes and marsupials) to Australia. The oldest fossils that have been found are probably Early Miocene in age (6). Interest in the subject has been stimulated by the profound changes in the thinking of geologists that have occurred during the past decade on the old problem of a postulated supercon...