13]C values relative to the international standard, Pee Dee Belemnite
One plesiosaur's stomach cavity included belemnite
remains, but 92 percent of the contents were crushed shells of thumb-size clams and snails.
13]C values were measured against Vienna Pee Dee Belemnite
Isotope data were expressed relative to Vienna Pee Dee Belemnite
The isotope ratios were expressed using the 'delta' notation ([delta]), with units of per mL or parts per thousand (%o), relative to the marine limestone fossil Pee Dee Belemnite
standard (Craig 1953) for [delta][sup.
Isotope results are reported in the conventional [delta] notation as per mil deviation from the carbon isotopic ratio of the Pee Dee Belemnite
(Peterson and Fry 1987).
Some ichthyosaur remains contain hundreds of belemnite
shells and thousands of their hooks, says Martin.
2] from a reference tank calibrated previously versus a standard reference material (Pee Dee Belemnite
, PDB; NBS-19).
where X = sample; and S = the marine carbonate standard Vienna Peedee belemnite
, VPDB (Gao et al.
15]N values of the standard reference materials (Per Dee belemnite
and atmospheric nitrogen, respectively).
The standard materials to which the samples are compared are Pee Dee Belemnite
for carbon, air [N.
All isotopic data are given in the conventional delta notation, units of parts per thousand (%) relative to the Vienna Pee Dee Belemnite
standard as follows:
All measurements were reported in standard Vienna Pee Dee Belemnite
(VPDB) and notation as [differential][per thousand] (per mil), where