This paper studies the Late Cretaceous dinosaur eggshell fossils from the Xixia Basin, Henan Province, by microscopy and carbon isotope method. Careful observation under microscope revealed that all dinosaur eggshell ...This paper studies the Late Cretaceous dinosaur eggshell fossils from the Xixia Basin, Henan Province, by microscopy and carbon isotope method. Careful observation under microscope revealed that all dinosaur eggshell fossils consist of primary calcite and secondary calcite. The content of the former is about 60.5% and the latter 39.5% according to image analysis. The δ\{\}\+\{13\}C values of secondary carbonate mineral filling within the dinosaur eggs in the strata range from -5.63‰ to -5.68‰, with an average value of -5.65‰. The δ\{\}\+\{13\}C values of sixteen dinosaur eggshell fossils are in the range from -5.88‰ to -7.79‰. Then we calculated the δ\{\}\+\{13\}C values of primary carbonate minerals, ranging from -6.03‰ to -9.19‰. Based on the δ\{\}\+\{13\}C values of the primary carbonate, the ancient food type and food proportion of dinosaurs were deduced. The dinosaur’s food proportions of C\-3 plant and C\-4 plant are 61% and 39%, respectively. Finally, it is inferred that the palaeoclimate in the Xixia Basin should be a warm—sub\|humid—sub\|arid climate in the subtropical zone of the Xixia Basin.展开更多
文摘This paper studies the Late Cretaceous dinosaur eggshell fossils from the Xixia Basin, Henan Province, by microscopy and carbon isotope method. Careful observation under microscope revealed that all dinosaur eggshell fossils consist of primary calcite and secondary calcite. The content of the former is about 60.5% and the latter 39.5% according to image analysis. The δ\{\}\+\{13\}C values of secondary carbonate mineral filling within the dinosaur eggs in the strata range from -5.63‰ to -5.68‰, with an average value of -5.65‰. The δ\{\}\+\{13\}C values of sixteen dinosaur eggshell fossils are in the range from -5.88‰ to -7.79‰. Then we calculated the δ\{\}\+\{13\}C values of primary carbonate minerals, ranging from -6.03‰ to -9.19‰. Based on the δ\{\}\+\{13\}C values of the primary carbonate, the ancient food type and food proportion of dinosaurs were deduced. The dinosaur’s food proportions of C\-3 plant and C\-4 plant are 61% and 39%, respectively. Finally, it is inferred that the palaeoclimate in the Xixia Basin should be a warm—sub\|humid—sub\|arid climate in the subtropical zone of the Xixia Basin.