ABSTRACT A specimen of a juvenile individual of Dinochelys from the Dry Mesa Quarry, Morrison Formation, provides the first record of the skull and neck in this genus. Dinochelys is interpreted as related to Glyptops on the basis of a similar development of sculpture on the vertebral scutes of juven

AbstractMost herbivorous insect species are restricted to a narrow taxonomic range of host plant species. Herbivore species that feed on mustard plants and their relatives in the Brassicales have evolved highly efficient detoxification mechanisms that actually prevent toxic mustard oils from forming

Abstract The pollen donor and pollinator attractor hypotheses are non‐exclusive alternative explanations for the functions of the staminate flowers of andromonoecious plants. We tested assumptions and predictions of both hypotheses using the andromonoecious perennial Pseudocymopterus montanus (Apiac

The link between reproductive and vegetative ecology of flowering plants is rarely explored, despite its importance for understanding population processes and fitness. This link can be studied by using experimental or natural variation in seed input to the soil to assess how reproductive success aff

Soil denitrification is an ecologically important nitrogen removal mechanism that releases to the atmosphere the greenhouse gas N2O, an intermediate product from the reduction of NO3− to N2. In this study we evaluate the relationship between soil carbon and denitrification potential in watersheds wi

• Premise of study: A difference in chromosome numbers (ploidy variation) between species is usually considered a major barrier to gene flow. Therefore, it is surprising that little is known about whether ploidy variation, both within and among species, influences spatial patterns of interspecific h

Habitat patches often differ in environmental conditions, and the degree of environmental heterogeneity among patches is thought to influence population dynamics at the regional (metapopulation) scale. In a previous study, I found evidence of a source– sink dynamic in a metapopulation of the mayfly

There is a growing understanding of the role that bedrock weathering can play as a source of nitrogen (N) to soils, groundwater and river systems. The significance is particularly apparent in mountainous environments where weathering fluxes can be large. However, our understanding of the relative co

The increase in corolla length provides a rare example of a match between predicted and observed evolution of a plant trait in natural populations. The clinal properties are consistent with the hypothesis that habitat-mediated divergent selection on vegetative traits and pollinator-mediated selectio

Animals respond to alarm calls by increasing their antipredator behavior; however, responses may consistently differ by age or sex. Although several adaptive explanations have been proposed to account for age-dependent antipredator behavior, similar explanations are rarely extended to sex-specific r

The weathering of shale exerts an important control on the hydrochemical fluxes to river systems, thus influencing the global carbon, nutrient, and geochemical cycles. However, the quantitative understanding of shale weathering and its impact on global biogeochemical cycles remains inadequate due to

Abstract. Soil thickness plays a central role in the interactions between vegetation, soils, and topography, where it controls the retention and release of water, carbon, nitrogen, and metals. However, mapping soil thickness, here defined as the mobile regolith layer, at high spatial resolution rema

PremiseIndustrialization and human activities have elevated temperatures and caused novel precipitation patterns, altering soil moisture and nutrient availability. Predicting evolutionary responses to climate change requires information on the agents of selection that drive local adaptation and infl

It is found that, after over 100 years, these disturbed plant communities remained distinct from similar surrounding undisturbed areas, suggesting that biotic factors structure vegetation communities even hundreds of years following disturbance.

Uncertainties in the calculation of water and phosphorus budgets for a bottom‐withdrawal reservoir were determined for 1979–1982. Ungaged components of the water budget were estimated from the residual of measured terms. This residual accounted for less than 30% of total water input and for more tha

This study describes the stratigraphic characteristics and distribution of fluvial deposits of the Upper Cretaceous Williams Fork Formation in a portion of Rulison Field and addresses 3D geologic modelling of reservoir sand bodies and their associated connectivity. Fluvial deposits include isolated

Blooms of the river benthic diatom Didymosphenia geminata are an enigma because they occur under phosphorus-poor conditions. A recent proposal that ferric–ferrous iron redox shifts sequester the additional phosphorus needed to stimulate and sustain D. geminata blooms does not agree with published ex

Secondary transfer of pollen can occur when a second pollinator remobilizes grains that had already been transferred to a flower by a previous pollinator. We used a pollen-color dimorphism to measure components of secondary transfer by bumble bees visiting the lily Erythronium grandiflorum. Remobili

Stable isotope ratios of precipitation are useful tracers of climatic and hydrological processes. To better understand the isotope hydro-climatology of a high-elevation Rocky Mountain valley we collected meteoric water samples from Gunnison, Colorado, USA and determined stable isotope values for 239