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The Middle to Late Devonian Khoshyeilagh Formation successions are here reported from the Khoshyeilagh neck, Alborz Mountains, Northeastern Iran. This formation is very fossiliferous. The rugose coral Hexagonaria davidsoni occurs within Frasnian strata and is the first report of this species from the Khoshyeilagh Formation. [ABSTRACT FROM AUTHOR]

The microfloral and microfaunal assemblages of the MFZ11 foraminiferal biozone (late early SomervilleViséan; formerly V2a) are well developed in the Kiyasar section of the Sari area (central Alborz; northern Iran). Regionally, this biozone MFZ11 may be subdivided into three subzones. The lower subzone, MFZ11A, is characterized by the appearances of the algae Koninckopora tenuiramosa , coeloporellacean indet. Fourstonella fusiformis , and Nanopora anglica and, among the foraminifers, by the occurrence of Ammarchaediscus bozorgniai and the disappearance of Eoparastaffella simplex ; the absence of Uralodiscus rotundus , U. spp., and primitive Glomodiscus spp. in this subzone is noticeable. The next subzone, MFZ11B1, is well characterized by the appearance of Glomodiscus spp. ( G. oblongus and G. cf. miloni ) and the local range zone of Pararchaediscus , a genus emended herein and interpreted as a junior synonym of Archaediscus at the involutus stage and Propermodiscus ; only a few characteristic issinellacean and palaeoberesellacean algae are present in this subzone. Then, the last subzone, MFZ11B2, is characterized by Hemiarchaediscus (emended herein) and Glomodiscus miloni ; the upper part of this latter subzone is only marked by the apparent absence of the archaediscids and the presence of two incertae sedis algae: Crassikamaena scabrosa and Epistacheoides bozorgniai nov. sp. These assemblages indicate that at that time, Alborz remained located on the Perigondwanan southern border of the Palaeotethys, and was probably connected with the Urals as well as the northwestern branch the Palaeotethys, from Belgium to the Donets Basin. [ABSTRACT FROM AUTHOR]

The brachiopods from the upper part of the Mobarak Formation at the Kiyasar section in the eastern Alborz Mountains, northern Iran, have been studied in detail. Fifteen species assigned to 13 genera of Strophomenida, Orthotetida, Orthida, Productida, Athyridida and Spiriferida are described. The fauna is determined as early Viséan in age based on the presence of Eomarginifera paucispinosa, Grandispirifer mylkensis and Unispirifer sp., and their associated foraminifers Uralodiscus, Paraarchaediscus, Glomodiscus and Endothyra, though taxa ranging through the Tournaisian-Viséan are also present. A comparison of its palaeogeographical affinities with other faunas show that the Alborz brachiopod fauna maintains strong Palaeotethyan affinities based on its general similarities with those of Eurasia, North America and Australia. This is suggestive of a prevailing oceanic current that circulated between the northern and southern shelf sea of the Palaeotethys Ocean, with which the warm-water brachiopod taxa were widespread in the Palaeotethyan Realm through the early Viséan. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]