Results 71 to 80 of about 1,591,136 (306)
American Journal of Botany, EarlyView.Abstract Premise Although Pararaucaria seed cones were first described 90 years ago, only in the last dozen years have we discovered the greater extent of the species diversity and paleogeographic range of the genus. Pararaucaria is now known across the mid‐latitudes of the Lower Jurassic to Lower Cretaceous in the northern and southern hemispheres ...
Carole T. Gee +2 more
wiley +1 more source
Earth and Planetary PhysicsUsing long-term Whole Atmosphere Community Climate Model version 5 (WACCM5) simulations initialized with the climatology around the year 2000, we studied the anomalous distribution of planetary wave and gravity wave fluxes during distinct phases of the ...
ZiXuan Yu +3 more
doaj +1 more source
The Anatomical Record, EarlyView.Abstract Tyrannosaurus is viewed as a model organism in vertebrate paleontology, with numerous studies analyzing its feeding biomechanics. Nonetheless, the evolution of this feeding performance has been under‐addressed in Tyrannosauroidea, especially in basal tyrannosauroids. Here we used muscle‐force reconstruction and finite element analysis (FEA) to
Evan Johnson‐Ransom +4 more
wiley +1 more source
The spatial distribution of hydrogen ions at topside ionosphere in local daytime
Terrestrial, Atmospheric and Oceanic Sciences, 2017 Using DEMETER and DMSP satellite data, the spatial distribution of hydrogen ion (H+) in local daytime has been compared and analyzed. At 840 km of DMSP height, the seasonal variations of H+ density is basically symmetric, with similar density values near
Xuhui Shen Xuemin Zhang
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Redescription of the Triassic cynodont Cistecynodon parvus and reassessment of its phylogeny
The Anatomical Record, EarlyView.Abstract Cynodontia is an important subclade of Therapsida that first occurred in the late Permian. It includes extinct subclades which are the non‐mammaliaform cynodonts and Mammaliaformes, with the latter ultimately giving rise to crown mammals. The systematics of non‐mammaliaform cynodonts has been extensively studied and is relatively well‐resolved,
Erin S. Lund +4 more
wiley +1 more source
Extending the SBUV polar mesospheric cloud data record with the OMPS NP [PDF]
Atmospheric Chemistry and Physics, 2019 We have utilized Solar Backscatter Ultraviolet (SBUV) instrument measurements of atmospheric radiance to create a 40-year record of polar mesospheric cloud (PMC) behavior.
M. T. DeLand, G. E. Thomas
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Origin of the Frigid Period in the Northern Hemisphere [PDF]
Science, 1892 n ...
openaire +3 more sources
Clade‐wide morphological and functional variation of the sauropsid columella
The Anatomical Record, EarlyView.Abstract The columella (=stapes) is the middle ear bone of reptiles that transmits vibrations from the environment to the inner ear. It has been shown to exhibit extensive interspecific morphological disparity in several clades; however, its morphological variation and associated functional consequences remain poorly described.
John Peacock +4 more
wiley +1 more source
Comparing forward and inverse models to estimate the seasonal variation of hemisphere-integrated fluxes of carbonyl sulfide [PDF]
Atmospheric Chemistry and Physics, 2002 A simple inverse model is proposed to deduce hemisphere-integrated COS flux based on published time series of total column COS. The global atmosphere is divided into two boxes representing the Northern and Southern Hemispheres, and the total column ...
A. J. Kettle +5 more
doaj
Sources of atmospheric mercury in the tropics: continuous observations at a coastal site in Suriname [PDF]
Atmospheric Chemistry and Physics, 2012 Mercury measurements at a coastal site in Nieuw Nickerie (5°56' N, 56°59' W), Suriname, provide the only continuous records of atmospheric mercury in the tropics. Here we evaluate observations of total gaseous mercury (TGM) during 2007.
D. Müller +5 more
doaj +1 more source