Results 71 to 80 of about 1,602,454 (306)

Redescription of the Triassic cynodont Cistecynodon parvus and reassessment of its phylogeny

open access: yesThe 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

The stratospheric Brewer–Dobson circulation under different phases of the Stratospheric Polar Vortex Oscillation combined with different phases of the Quasi-Biennial Oscillation

open access: yesEarth and Planetary Physics
Using 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

Clade‐wide morphological and functional variation of the sauropsid columella

open access: yesThe 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]

open access: yesAtmospheric 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  

The spatial distribution of hydrogen ions at topside ionosphere in local daytime

open access: yesTerrestrial, 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
doaj   +1 more source

Postcranial anatomy and osteohistology of an early prozostrodont cynodont from the Upper Triassic of Brazil

open access: yesThe Anatomical Record, EarlyView.
Abstract Prozostrodon brasiliensis, a probainognathian cynodont of the clade Prozostrodontia, is recognized as a key taxon for understanding the origin of Mammaliaformes and mammals. Despite detailed investigations of its cranial anatomy, the postcranial skeleton has received comparatively less attention.
Iasmim M. Michelotti   +4 more
wiley   +1 more source

Extending the SBUV polar mesospheric cloud data record with the OMPS NP [PDF]

open access: yesAtmospheric 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
doaj   +1 more source

Exceptional preservation informs the paleobiology of tapinocephalid dinocephalians

open access: yesThe Anatomical Record, EarlyView.
Abstract The tapinocephalid dinocephalian Moschops is one of the most iconic taxa of the middle Permian, yet its paleobiology remains one of the least well‐known. Here, we address some aspects of paleoneurology and paleobiology of Moschops using CT scanning of four well preserved skulls from the upper Abrahamskraal Formation of South Africa. Two of the
Julien Benoit   +6 more
wiley   +1 more source

Sources of atmospheric mercury in the tropics: continuous observations at a coastal site in Suriname [PDF]

open access: yesAtmospheric 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

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