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Djadochta Formation
The Djadochta Formation (sometimes transcribed Djadokhta) is a geological formation situated in central Asia (Gobi Desert), dating from the Late Cretaceous Period. Laid down in the early Campanian, possibly starting in the latest Santonian, it is dated somewhat uncertainly at about 75-71 mya (million years ago). The type locality are the famous "Flaming Cliffs", locally known as ''Bayanzag'' ("rich in ''Haloxylon''") or ''Ulaan-Ereg'' ("red cliffs").
It preserves an arid habitat of sand dunes, with little freshwater apart from oases and arroyos. In fact, the present-day climate at most Djadochta Formation sites differs little from what it was some 80 mya, except by being somewhat warmer and perhaps a bit less arid then. This is testimony to the fact that the location has long been so far from any major source of evaporation that little rainfall reached it, even before the Himalayas were uplifted which bar clouds from reaching today's Gobi desert.
Most notable fossil discoveries have been the first confirmed dinosaur eggs (a clutch, probably of ''Oviraptor'') and several dinosaur finds, ''Protoceratops'', ''Pinacosaurus'' and ''Velociraptor'' being the most prominent.
==Fauna==
The fauna of the Djadochta Formation is very similar in composition to the nearby Bayan Mandahu Formation. The two share many of the same genera, but differ in the exact species. For example, the most common mammal in the Djadochta is ''Kryptobaatar dashzevegi'', while in the Bayan Mandahu, it is the closely related ''Kryptobaatar mandahuensis''. Similarly, the dinosaur fauna of the Djadochta includes ''Protoceratops andrewsi'' and ''Velociraptor mongoliensis'', which the Bayan Mandahu yields ''Protoceratops hellenikorhinus'' and ''Velociraptor osmolskae''.〔 It is likely that the nearby Bayn Mandahu represents a slightly younger, perhaps by 1 million years, assemblage of slightly more derived animals, possibly the direct descendants of their Djadochta counterparts.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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