Objective The oofamily Dendroolithidae is elliptical or oblate eggs with loosely arranged dendritic eggshell units and large cavities between eggshell units (Zhang et al., 2018).Dendroolithidae is represented by two o...Objective The oofamily Dendroolithidae is elliptical or oblate eggs with loosely arranged dendritic eggshell units and large cavities between eggshell units (Zhang et al., 2018).Dendroolithidae is represented by two oogenera,Dendroolithus (Zhao Zikui and Li Zuocong, 1988), and Placoolithus (Zhao Hong and Zhao Zikui, 1998)according to the latest classification (Zhang et al., 2018).展开更多
The record of dinosaur eggs from the Upper Cretaceous Wangshi Group in eastern Shandong Province,China shows that the dinosaur species represented by elongatoolithids were present from the middle to the late Late Cret...The record of dinosaur eggs from the Upper Cretaceous Wangshi Group in eastern Shandong Province,China shows that the dinosaur species represented by elongatoolithids were present from the middle to the late Late Cretaceous,whereas those represented by the dictyoolithids and spheroolithids became extinct in the middle Late Cretaceous and the new species represented by ovaloolithids appeared in the late Late Cretaceous.Estimated eggshell conductance of water vapor is over 4 to over 115 times higher in spheroolithids and the dictyoolithids than in elongatoolithids and ovaloolithids,indicating that eggs of the first two oofamilies required higher humidity during incubation.Based on the18O record as preserved in eggshell,a change from relatively humid to relatively dry climatic conditions can be assumed to have taken place during the transition between the middle and late parts of the Late Cretaceous.It is reasonable to suggest that the change in climate was the cause of the dinosaur diversity.展开更多
基金supported by the National Natural Science Foundation of China (grant No. 41802006)the Natural Science Foundation of Anhui Province (grant No. 1708085QD86)the University Natural Science Research Project of Anhui Province (grant No. KJ2018A0005)
文摘Objective The oofamily Dendroolithidae is elliptical or oblate eggs with loosely arranged dendritic eggshell units and large cavities between eggshell units (Zhang et al., 2018).Dendroolithidae is represented by two oogenera,Dendroolithus (Zhao Zikui and Li Zuocong, 1988), and Placoolithus (Zhao Hong and Zhao Zikui, 1998)according to the latest classification (Zhang et al., 2018).
基金supported by the National Natural Science Foundation of China(41172018 and 41202003)the National Key Basic Research Program of China(2012CB821900)the Special Founds for the Paleontology and Paleoanthropology,Academia Sinica(9118)
文摘The record of dinosaur eggs from the Upper Cretaceous Wangshi Group in eastern Shandong Province,China shows that the dinosaur species represented by elongatoolithids were present from the middle to the late Late Cretaceous,whereas those represented by the dictyoolithids and spheroolithids became extinct in the middle Late Cretaceous and the new species represented by ovaloolithids appeared in the late Late Cretaceous.Estimated eggshell conductance of water vapor is over 4 to over 115 times higher in spheroolithids and the dictyoolithids than in elongatoolithids and ovaloolithids,indicating that eggs of the first two oofamilies required higher humidity during incubation.Based on the18O record as preserved in eggshell,a change from relatively humid to relatively dry climatic conditions can be assumed to have taken place during the transition between the middle and late parts of the Late Cretaceous.It is reasonable to suggest that the change in climate was the cause of the dinosaur diversity.
