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The Jebel Qatrani Formation is a palaeontological formation located in Egypt, conformably overlying the Qasr el Sagha Formation. It is exposed namely between the Jebel Qatrani escarpment and the Qasr el Sagha escarpment, north of Birket Qarun lake near Faiyum. These rocks were laid down in the Eocene-Oligocene period (Priabonian - Rupelian). This formation was some time placed entirely in the Oligocene, but recent opinion holds the original hypothesis of a sediment straddling the Eo-Oligocene boundary to be correct. Mostly sandstones deposited by meandering rivers and seasonal lakes, the lower (Eocene) part of the formation represents a woodlanded ecosystem of which lots of petrified wood also remain. In contrast, the upper (Oligocene) layers present indication of much drier and cooler conditions, with savanna replacing the woodland for several million years before the climate turned wetter and warmer again and the forests regrew. The fauna changes also notably during this time, which seems to be coincident with the Eocene–Oligocene extinction event recorded in Eurasia. ==Fossils== Mammals * ''Arsinoitherium zitteli'', an arsinoitheriid * ''Bothriogenys fraasi'', an anthracotheriid * ''Herodotius pattersoni'', a pseudoungulate * ''Plesiopithecus'', an enigmatic lemur-like primate * Pliohyracidae, large hyraxes * Ptolemaiida, carnivorous afrothere mammals * ''Qatranilestes'' and ''Widanelfarasia'', relatives of golden moles, otter shrews and tenrecs * Several hyaenodontids (''Akenatenavus cf. leptognathus, Metapterodon'') * Several hystricognath rodents (e.g. ''Acritophiomys bowni, A. woodi, Elwynomys lavocati, Gaudeamus hylaeus'') * A primitive marsupial, maybe related to ''Peratherium'' * Primitive Old World monkeys (e.g. ''Aegyptopithecus, Biretia fayumensis, B. megalopsis'') Birds * ''Eremopezus'', an enigmatic large groundbird * ''Goliathia'', a large shoebill relative * ''Palaeoephippiorhynchus dietrichi'', a large stork * ''Xenerodiops'', an unusual heron * A cormorant-like bird possibly related to ''Piscator'' * Several jacanas * One or two species of primitive osprey and another bird of prey (possibly an ancestral sea eagle) * A turaco Other * ''Albertwoodemys'', a side-necked turtle * ''"Crocodylus" megarhinus'', an ancestral crocodile * ''Eogavialis africanum'', a primitive gharial * ''Parachanna fayumensis'', a snakehead fish * ''Pterosphenus'', a snake * African tetras (Alestidae) or similar Characiformes * Catfish, perhaps of genus ''Fajumia'' 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Jebel Qatrani Formation」の詳細全文を読む スポンサード リンク
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