International: Biostratigraphy, Biogeography, and Phylogeny of Vertebrates from the World's Oldest Known, Eutherian Dominated Fauna (Dzharakuduk, Uzbekistan)

100米，上白垩纪Dzharakuduk部分（Kyzylkum沙漠，乌兹别克斯坦）包括河流和海洋沉积物，产生超过100种脊椎动物。 在这些地点收集微型脊椎动物是由已故的俄罗斯古生物学家Nessov开始的，并由乌兹别克，俄罗斯，英国，美国和加拿大（URBAC）科学家组成的国际财团继续进行。 从该剖面上部采集到的大量新的海洋无脊椎动物，可以与欧洲的模式剖面相关联，表明科尼亚阶/桑托阶时代（约8500万年）。 这再次证实了底层的陆生脊椎动物至少有8500 - 9000万年的历史，因此比更著名的戈壁沙漠遗址更古老。 当地丰富的脊椎动物遗骸是零碎的，但往往保存精美的细节。 大多数化石被迅速掩埋，可能是由于山洪暴发，几乎没有再加工。 古生态与晚白垩世北美沿海平原相似。 从新筛选的55吨基质中，翼龙、哺乳动物和恐龙的颅后和颅部成分仍然很常见。 在两栖动物中，蝾螈比青蛙更常见。 在爬行动物中，水生龟类、鸭嘴龙类和鸭嘴龙类的恐龙碎片很常见，而蜥蜴类、小型兽脚亚目、甲龙类、角龙类和蜥脚亚目恐龙则相对罕见。 鸟类种类繁多，既有已灭绝的类群，也有与现存鸟类关系较近的物种。 啮齿类多瘤哺乳动物和有袋类哺乳动物的亲属是罕见的。 真兽目哺乳动物是人类所属的哺乳动物，是Dzharakuduk最常见的哺乳动物物种，约有11种。 其中包括世界上最早的亲戚，产生了啮齿动物和兔子，以及可能产生了至少七个有蹄哺乳动物和鲸鱼的群体。 所有迹象都表明，以前的工作才刚刚开始揭示Dzharakuduk的化石财富。 未来三年的工作将为这些8500万至9000万年前的脊椎动物群提供许多剩余问题的答案。

The 100m, Upper Cretaceous Dzharakuduk section (Kyzylkum Desert, Uzbekistan) includes river and marine sediments that yield over 100 species of vertebrates. Collecting microvertebrates at these sites was begun by the late Russian paleontologist Nessov and has been continued by an international consortium of Uzbek, Russian, British, American, and Canadian (URBAC) scientists. Large, new collections of marine invertebrate from the upper part of the section that can be correlated to type sections in Europe, indicate a Coniacian/Santonian age (about 85 million years old). This reconfirms that the underlying terrestrial vertebrates are at least 85-90 million years old, thus older than the more famous Gobi Desert sites. Locally abundant vertebrate remains are fragmentary, but often preserve exquisite detail. Most fossils were rapidly buried, possibly by flash floods, with little reworking. Paleoecology is similar to the Late Cretaceous North American coastal plains. Postcranial and cranial elements of pterosaurs, mammals, and dinosaurs remain common from the newly screened 55 tons of matrix. Among amphibians, salamanders are much more common than frogs. Among reptiles, aquatic turtles, and hadrosaur and tyrannosaur dinosaur fragments are common, while lizards, small theropod, ankylosaur, ceratopsian, and sauropod dinosaurs are relatively rare. Birds are diverse, including both extinct groups, as well as species closer to living birds. The rodent-like multituberculate mammals and relatives of marsupial mammals are rare. Eutherian mammals, the group of mammals to which humans belong, are the most common mammalian species at Dzharakuduk, with some 11 species. These include the world's earliest relatives of the group that gave rise to rodents and rabbits, as well as the group that may have given rise to at least seven orders of hoofed mammals and whales. All indications show that previous work has only begun to uncover the fossil riches of Dzharakuduk. The next three years of work there will provide answers to many of the remaining questions regarding these 85-90 million-year-old vertebrate faunas.