Table 1: Stable isotope data from modern eggshells. Data are compared with published calibrations in Fig. 1.

From: Isotopic ordering in eggshells reflects body temperatures and suggests differing thermophysiology in two Cretaceous dinosaurs

SpeciesCommon name# n analyses*δ13Ceggshell‰, V-PDBδ18Oeggshell‰, V-PDBΔ47‰, ARFΔ47 1 s.e.Δ47 Temp. (oC) inorganic eq.Δ47 Temp. (oC) biogenic eq.§1 s.e.Temp. (oC) expected||δ18Owater‰, V-SMOW
Pipilo erythrophtalmusEastern towhee2−13.9−4.60.6220.00245.445.30.643.31.6
Sayornis phoebeEastern phoebe1−13.6−1.10.6250.01244.744.43.443.35.0
Vanellus milesMasked lapwing3−3.9−2.80.6500.00538.537.51.342.02.0
Gallus gallus domesticusDomestic chicken23.3−4.60.6360.00841.941.
Odontophorus melanotisWood quail2−3.1−1.20.6380.00541.440.81.441.54.2
Irena puellaAsian fairy bluebird2−8.7−0.60.6400.00340.940.20.841.04.7
Columba liviaRock pigeon4−3.0−1.70.6370.00341.741.10.841.03.8
Cathartes auraTurkey vulture2−9.5−4.50.6500.01138.537.52.939.90.3
Struthio camelusCommon ostrich3−12.6−3.90.6430.00240.239.40.539.11.3
Cygnus atratusBlack swan4−5.1−11.30.6460.01339.538.63.539.0−6.3
Tyto albaBarn owl4−16.1−3.10.6380.01241.440.83.338.72.3
Dromaius novaehollandiaeEmu3−8.3−14.30.6550.00737.336.21.838.0−9.8
Spheniscus magellanicusMagellanic penguin5−11.4−7.50.6430.01140.−2.4
Varanus gouldiiMonitor lizard2−13.6−3.00.6740.04633.031.311.033.5–36.30.6
Geochelone radiataRadiated tortoise3−14.7−5.40.6660.01034.833.32.531–34−1.4
Alligator mississippiensisAmerican alligator3−13.4−16.60.6810.00131.429.50.229–33−13.4
Crocodylus acutusAmerican crocodile4−12.5−3.80.6740.00733.031.31.829–33−0.2
Chelonoidis nigraGalapagos giant tortoise2−16.5−8.60.6680.00734.332.81.828–32−4.7
Podocnemis sp.Turtle4−14.5−5.40.6800.00731.629.81.728–32−2.1
Pantherophis guttatusCorn snake4−10.4−4.60.6790.00931.830.02.227–29−1.2
Crocodylus niloticusNile crocodile3−9.2−2.50.6890.00729.627.61.727–280.4
Heloderma horridum exasperatumBeaded lizard1−8.9−0.20.6730.00933.231.52.326–302.3
  1. *Represents the number of distinct extractions of CO2 from a sample that is then purified and analysed. In each case just one eggshell specimen was analysed. s.d. is reported if only two analyses were made.
  2. Values given on the ‘absolute reference frame’ or ARF20.
  3. Calculated using the inorganic calibration of Ghosh et al.19 (Equation (2); Supplementary Note 2).
  4. §Calculated using a compilation of published biogenic calibration (Equation (3), Supplementary Note 2) data collected in the Caltech laboratories and synthesized by Eagle et al.26. See Supplementary Note 2 for more information on how this calibration was derived.
  5. ||From observations of modern animals—sources listed in Supplementary Note 2 and Supplementary Tables 5 and 6.
  6. δ18O of body waters calculated using published mineral-specific equations and using the Δ47 (Biogenic) temperature. All eggshells are calcite, except for turtle and tortoise eggshells that are aragonite.