Table 2 Stable isotope data from Cretaceous eggshells and associated phases.

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

Species or material*

Locality

n specimens

n analyses †

δ 13 C CO3 ‰, V-PDB

δ 18 O CO3 ‰, V-PDB

Δ 47 ‰, ARF §

Δ 47 Temp. (°C) inorganic eq. ||

Δ 47 Temp. (°C) biogenic eq.

δ 18 O water ‰, V-SMOW #

Apparently well-preserved eggshells:

 Oviraptorid

Ukhaa Tolgod

3

9

−5.7±0.3

−2.1±0.2

0.671±0.012

30.3±2.6

31.9±2.9

1.6±0.2

 Titanosaurid

Auca Mahuevo, level 4

3

7

−12.7±0.0

0.4±0.0

0.650±0.006

35.3±1.4

37.6±1.9

5.2±0.2

Eggshells of uncertain preservation:

 Putative titanosaurid

Rousset, layers B–D

6

7

−9.2±0.3

−4.8±0.1

0.642±0.005

37.0±1.2

39.6±1.4

0.4±0.3

 Oviraptorid

Bugin Tsav

3

7

−5.5±0.3

−9.7±1.3

0.674±0.005

29.7±1.0

31.3±1.2

−6.4±0.5

 Oviraptorid

Bayn Dzak

1

2

−3.6±0.0

−11.5±0.1

0.684±0.014

27.5±2.9

28.8±3.3

−8.4±1.3

 Morphotype 2

Ukhaa Tolgod

4

13

−5.7±0.2

−3.0±0.4

0.667±0.003

31.2±0.8

32.9±0.8

1.0±0.3

Poorly preserved eggshells:

 Oviraptorid

Ukhaa Tolgod

2

8

−6.6±0.3

−8.1±0.2

0.681±0.009

28.2±1.9

29.6±2.2

−4.8±0.8

 Titanosaurid

Auca Mahuevo, level 2

4

8

−12.6±0.1

−0.2±0.1

0.624±0.004

41.6±0.9

44.8±1.0

6.0±0.1

 Putative titanosaurid

Roques Hautes

3

6

−10.5±0.4

−3.4±0.7

0.616±0.013

43.6±3.3

47.0±3.8

3.2±1.1

 Putative titanosaurid

Rousset, layer A

3

6

−13.2±0.2

1.2±0.6

0.633±0.001

39.4±0.4

42.3±0.4

6.9±0.6

Associated phases:

 Nodular carbonates

Ukhaa Tolgod

9

9

−3.3±0.2

−11.0±0.3

0.694±0.011

25.2±2.3

26.3±2.6

−7.9±0.3

 Spar calcite

Ukhaa Tolgod

1

1

−6.4±0.0

−12.2±0.0

0.689±0.007

26.4±1.4

27.6±1.6

−8.9±0.4

 Bone

Ukhaa Tolgod

1

1

−3.6±0.0

−11.7±0.0

0.668±0.010

31.0±2.1

32.8±2.4

−7.5±0.6

 Nodular carbonates

Roques Hautes

7

7

−8.9±0.1

−4.9±0.1

0.641±0.006

37.4±1.5

40.0±1.7

0.0±0.2

 Bulk sediment

Auca Mahuevo, level 2

1

1

−9.8±0.0

−4.6±0.0

0.630±0.007

40.0±1.8

43.0±2.0

1.2±0.5

  1. ± Values are one s.e., or in the case of water isotope values, the propagated s.e.
  2. *Samples were considered to be of uncertain preservation if not enough information from multiple sources was available to make an informed assessment or if different types of analyses were not conclusive. See Supplementary Note 3 for full description of steps taken to assess preservation, and Supplementary Table 4 for justification for classification of individual specimens.
  3. †Represents the number of distinct extractions of CO2 from a sample that were separately purified and analysed. See Supplementary Table 3 for additional data for samples.
  4. Stable isotope values of the carbonate mineral.
  5. §Values given on the ‘absolute reference frame’20.
  6. ||Calculated using the inorganic calibration of Ghosh et al.19 (Equation (2); Supplementary Note 2).
  7. 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 text for more information on how this calibration was derived.
  8. #δ18O of mineral formation waters calculated using the equation of Kim and O’Neil38, and using the Δ47 (Biogenic) temperature). All eggshells are calcite. Error represents propagated one s.e.
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