نتایج جستجو برای: lower paleogene
تعداد نتایج: 692919 فیلتر نتایج به سال:
abstract the variables affecting the nature of reading comprehension can be classified into two general categories: reader’s variables, and text variables (alderson, 2000). despite the wave of research on vocabulary knowledge as reader’s variable, the role of this knowledge in c-test as a text-dependent test and its interaction with lexical cohesion of the test as a text feature has remained a...
Mitchell et al. argue that divergence-time estimates for our avian phylogeny were too young because of an “inappropriate” maximum age constraint for the most recent common ancestor of modern birds and that, as a result, most modern bird orders diverged before the Cretaceous-Paleogene mass extinction event 66million years ago instead of after. However, their interpretations of the fossil record ...
Jarvis et al. (Research Articles, 12 December 2014, p. 1320) presented molecular clock analyses that suggested that most modern bird orders diverged just after the mass extinction event at the Cretaceous-Paleogene boundary (about 66 million years ago). We demonstrate that this conclusion results from the use of a single inappropriate maximum bound, which effectively precludes the Cretaceous div...
چکیده برش ورکمر در شمال اصفهان، واقع در حاشیه غربی پلیت ایران مرکزی و چسبیده به حاشیه شرقی زون سنندج - سیرجان می باشد. سنگ های آتشفشانی منطقه مربوط به فعالیت آتشفشانی ائوسن و قابل مشاهده در ارتفاعات کرکس می باشد. شکل ساختمانی منطقه در نتیجه جنبش های تکتونیکی مربوط به ژوراسیک بالایی و سپس در اواخر کرتاسه و به خصوص در طی دوران سوم اتفاق افتاده است که بر این اساس نهشته های دونین زیرین تا ائوسن قا...
This review article summarizes the recent work done in India on fossil vertebrates from the Mesozoic-early Paleogene interval, with focus on the past five years. Advances made during this period highlight the importance of India’s vertebrate fossil record in our understanding of the origin and evolutionary history of several vertebrate groups and the dynamics of intercontinental faunal dispersa...
Molecular phylogeny suggests a close relationship of Asteraceae to the early evolution of Golovinomyces. The family Asteraceae, with a geographic origin in South America, expanded into the Northern Hemisphere, where it may have been infected by an ancestor of Golovinomyces, thus starting a close hosteparasite relationship. Using this event as a calibration point, we designed molecular clocks fo...
The mass extinction of life 66 million years ago at the Cretaceous/Paleogene boundary, marked by the extinctions of dinosaurs and shallow marine organisms, is important because it led to the macroevolution of mammals and appearance of humans. The current hypothesis for the extinction is that an asteroid impact in present-day Mexico formed condensed aerosols in the stratosphere, which caused the...
simplification universal as a universal feature of translation means translated texts tend to use simpler language than original texts in the same language and it can be critically investigated through common concepts: type/token ratio, lexical density, and mean sentence length. although steps have been taken to test this hypothesis in various text types in different linguistic communities, in ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید