|
Udurchukan Formation
The Udurchukan Formation is a geological formation located in Amur Region, Far East Russia. Based on palynomorphs such as ''Wodehouseia spinata'' the Udurchukan is considered of Maastrichtian age of the Late Cretaceous, during the Cretaceous Period. Fossil record Inasmuch as '' Wodehouseia spinata'' and '' Aquillapollenites subtilis'' are known in the Americas only from the Late Maastrichtian, the presence of these palynomorphs in the Udurchukan caused Godefroit to consider the unit and its lambeosaur dominated fauna to be coeval with the Lance Formation and Hell Creek Formation. However, research in the Songliao Basin indicates ''Wodehouseia spinata'' is also known from the early (albeit not basal) and middle Maastrichtian of Asia. The latest view, appearing in the paper on comparative osteology of '' Edmontosaurus'' and ''Shantungosaurus'', is that one Udurchukan Formation locality, Kundur, is late−early Maastrichtian; and the other, Blagoveschensk, is early−late Maast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about wide colliding with Earth, ending the Cretaceous. Stratigraphic definitions Definition The Maastrichtian was introduced into scientific literature by Belgian geologist André Hubert Dumont in 1849, after studying rock strata of the Chalk Group c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
