نتایج جستجو برای: mesozoic
تعداد نتایج: 2523 فیلتر نتایج به سال:
Variation in the geographic spread of fossil localities strongly biases inferences about the evolution of biodiversity, due to the ubiquitous scaling of species richness with area. This obscures answers to key questions, such as how tetrapods attained their tremendous extant diversity. Here, we address this problem by applying sampling standardization methods to spatial regions of equal size, w...
■ Abstract Vertebrate dispersal of fruits and seeds is a common feature of many modern angiosperms and gymnosperms, yet the evolution and frequency of this feature in the fossil record remain unclear. Increasingly complex information suggests that (a) plants had the necessary morphological features for vertebrate dispersal by the Pennsylvanian, but possibly in the absence of clear vertebrate di...
In 1840, John Phillips invented the term Mesozoic, which means “Middle Animal”. The Mesozoic Era was a geological time period that lasted 180 million years and is composed of three smaller time periods, Triassic, Jurassic and the Cretaceous. The cretaceous period lasted 81 million years, which during that time there was a continual rule of dinosaurs and other reptiles, the start of flowering pl...
Variation in daily activity patterns facilitates temporal partitioning of habitat and resources among species. Knowledge of temporal niche partitioning in paleobiological systems has been limited by the difficulty of obtaining reliable information about activity patterns from fossils. On the basis of an analysis of scleral ring and orbit morphology in 33 archosaurs, including dinosaurs and pter...
Several studies have attempted to determine the lower limit of atmospheric oxygen under which combustion can occur; however, none have been conducted within a fully controlled and realistic atmospheric environment. We performed experimental burns (using pine wood, moss, matches, paper, and a candle) at 20 degrees C in O2 concentrations ranging from 9 to 21% and at ambient and high CO2 (2000 par...
Traveling through time has become extremely popular. Since H.G. Wells’ famed novel, scientists have designed machines that can actually beam you into the future or into the deepness of time with the snap of a finger. Of course, destinations vary. Engineers and architects have a preference for Giza, 4,500 years ago, when the Great Pyramid was built. Resort enthusiasts might fancy the Dulce Vita ...
This paper presents a new interpretation of the geometry of Triassic alignment of J. Sidi Mahdi –J. Zitoun in Medjerda Valley Plain (Northern Tunisia) based on detailed analysis of gravity and seismic reflection data. The main results of gravity analysis do not show a distinguish gravity anomaly over Triassic evaporites bodies. The positive gravity anomaly seems to be related to the entire stru...
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