• journal_title：PALAIOS
• Contributor：LAURA DOMINGO ; FERNANDO BARROSO-BARCENILLA ; OSCAR CAMBRA-MOO
• Publisher：SEPM Society for Sedimentary Geology
• Date：2013-03-01
• Format：text/html
• Language：en
• Identifier：10.2110/palo.2012.p12-097r
• journal_abbrev：PALAIOS
• issn：0883-1351
• volume：28
• issue：3
• firstpage：195
• section：Research Note

Stable isotope analyses (δ¹⁸O_PO4, δ¹⁸O_CO3, and δ¹³C) are reported for the first time on crocodilian, theropod, and sauropod teeth from two stratigraphic levels (G1 and G2) from the late Campanian–early Maastrichtian “Lo Hueco” fossil site (Cuenca, Spain) in order to better understand paleoclimatic and paleoenvironmental conditions existing in the Iberian Peninsula during the Late Cretaceous. Diagenetic alteration was evaluated using three tests: (1) consistent differences in enamel and dentine δ¹⁸O_PO4 values, (2) crocodilian δ¹⁸O_PO4 values consistently lower than dinosaur δ¹⁸O_PO4 values in agreement with the proposed latitudinal distribution between ectotherms and endotherms, and (3) a Δδ¹⁸O_CO3-PO4 value of 9.1 ± 1.7‰ for dinosaurs in accordance with the expected equilibrium fractionation between carbonate and phosphate in unaltered modern mammalian bioapatite. Calculated δ¹⁸O_H2O values are slightly higher in crocodilians compared to dinosaurs since semiaquatic ectothermic taxa δ¹⁸O_H2O represents local meteoric waters in a brief window of time when the conditions are favorable for apatite synthesis, whereas terrestrial endothermic taxa δ¹⁸O_H2O records ingested water year-round. Mean air temperature calculated using crocodilian and dinosaur δ¹⁸O_H2O values shows an increase between G1 and G2, which may be related to differences in the sedimentological setting and/or to a shift toward warmer conditions over time. Finally, the sauropod mean δ¹³C value (−11.1 ± 0.2‰, VPDB) is in the predicted range for C₃ vegetation.