Leaf miners typically show non-random distributions both between and within plants. We tested the hypothesis that leaf miners on two oak species were clumped on individual host trees and individual branches and addressed whether clumping was influenced by aspects of plant quality and how clumping and/or interactions with other oak herbivores affected leaf-miner survivorship. Null models were us...

RATIONALE The measurement of multiply substituted isotopologues of CO2 derived from carbonate has allowed the reconstruction of paleotemperatures from a single phase (CaCO3 ), circumventing uncertainty inherent in other isotopic paleothermometers. Traditional analytical techniques require relatively large amounts of carbonate (3-8 mg per replicate), which limits the applicability of the clumped...

We present a revised approach for standardizing and reporting analyses of multiply substituted isotopologues of CO2 (i.e., ‘clumped’ isotopic species, especially the mass-47 isotopologues). Our approach standardizes such data to an absolute reference frame based on theoretical predictions of the abundances of multiply-substituted isotopologues in gaseous CO2 at thermodynamic equilibrium. This r...

Critical biodiversity has been defined as the level of species richness at which communities are most susceptible to disturbance, where even small perturbations resulting from the introduction or extinction of a single species may trigger a mass extinction event. Beyond this threshold, it has been hypothesized that ordered communities with well-defined spatial structure will spontaneously form;...

We apply the carbonate clumped isotope thermometer (D47) to macrofossils from the Baculites compressus ( 73.5 Ma) and the Hoploscaphites nebrascensis ( 67 Ma) ammonite zones of the Western Interior Seaway (WIS) of North America, and nearby coeval terrestrial and open marine environments. The carbonate clumped isotope thermometer is based on a single-phase isotope exchange equilibrium that promo...