A stratigraphic section from the Tirgan Formation was selected in Arkan village nearby Bojnourd city in order to study echinoderm fauna systematically. Many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. Microscopie slides were also prepared and studied. All slides contain benthic foraminifers and c...

We investigate the evolutionary history of the wide-ranging Nearctic treefrog Hyla arenicolor through the integration of extensive range-wide sampling, phylogenetic analyses of multilocus genetic data, and divergence dating. Previous phylogeographic studies of this frog documented a potential signature of introgressive hybridization from an ecologically and morphologically divergent sister spec...

This study shows that ichonology can be used to refine sequence stratigraphy as well as to interpret the depositional environment of the Kalat Formation (Upper Maastrichtian) in the Central Kopeh- Dagh Basin (NE Iran), Dareh-Gaz section. Field studies and petrography of these deposits led to recognize four lithofacies and nine subfacies that formed in the tidal flat (lithofacies A), lagoon (lit...

The Upper Cretaceous strata were studied in a composite stratigraphic section named here Padeha-Baghak section in east of Koppeh-Dagh basin, north east of Iran. In this study, palynostratigraphy, palynofacies and depositional environment history of Abderaz Formation were integrated with sequence stratigraphy. Determination of sea level history and sequence units of the Abderaz Formation using s...

this study shows that ichonology can be used to refine sequence stratigraphy as well as to interpret the depositional environment of the kalat formation (upper maastrichtian) in the central kopeh- dagh basin (ne iran), dareh-gaz section. field studies and petrography of these deposits led to recognize four lithofacies and nine subfacies that formed in the tidal flat (lithofacies a), lagoon (lit...

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