Early Jurassic corals of the Pamir Mountains - a new Triassic-Jurassic transitional fauna
Institute of Geology, Earthquake Engineering and Seismology, Aini 267, 734063 Dushabe, Tadjik Republic; mgk-36@mail.ru
Institute of Paleobiology PAN, Twarda 51/55, 00-818 Warszawa, Poland; eron@twarda.pan.pl
Abstract
Four microstructural groups of corals representing the orders Scleractinia and Hexanthiniaria are known in the Triassic and in the Early Jurassic of the Tethys realm. In the south-eastern Pamir Mountains, Lower Jurassic corals occur from the Hettangian to Toarcian sediments. Hettangian?-Sinemurian and Sinemurian coral faunas discussed in this paper come from the Gurumdy and Mynkhajir facies zones. Coral associations are composed of classical Early Jurassic West European and North African (Moroccan) taxa, accompanied by several genera previously unknown in the West Tethys. After the end-Triassic extinction, the Early Jurassic recovery faunas of the Pamir Mountains contain Stylophyllopsis, Eocomoseris, a genus related to Elysastrea, and a large number of Jurassic genera: Oppelismilia, Archaeosmilia, Archaeosmiliopsis, Stylosmilia, Proaplophyllia, Cylismilia, Intersmilia, Prodonacosmilia, Pachysmilia, Placophyllia and Stephanastraea. More or less fragmented corals and complete skeletons are found in detrital carbonate, oolitic, or micritic limestone facies. Phaceloid growth forms prevail over solitary and massive ones.