The Zhutian and Dafeng formations(Upper Cretaceous) of the Heyuan Basin in northeastern Guangdong Province,China,have produced thousands of dinosaur eggs.Macromorphological features(egg diameter,egg shape,outer surface texture,and shell thickness) of 461 eggs were analyzed using non-destructive techniques and subjected to statistical analyses in order to assess their diversity and taxonomic affinities.Three types(1,2 and 3) of eggs were discerned based on shape and outer surface morphology.Type 1 eggs are spherical to ellipsoidal in shape and have a rough surface.Three subtypes(Type 1-A-1,1-A-2,and 1-B) are apparent from scatter plots and cluster analyses of egg diameters and shell thickness.Type 2 eggs are elongate with linear ornamentation on the surface,and are comparable to eggs that belong to the oofamily Elongatoolithidae.Type 3 eggs are elongate with a smooth surface,and are assigned to the oofamily Prismatoolithidae.Macromorphological features of the various egg types suggest that Type 1 could have been laid by ornithischian,sauropod or therizinosaur dinosaurs,Type 2 by oviraptorids,and Type 3 by troodontids.This study represents the first comprehensive statistical analysis of macrofeatures of dinosaur eggs,and reveals taxonomic diversity in the dinosaurs that were laying eggs in the Upper Cretaceous Heyuan area heretofore unrecognized in skeletal remains.
Kohei TANAKALU JunchangLIU YiHUANG ZhiqingYoshitsugu KOBAYASHIHUANG DongDarla K. ZELENITSKY
The sequence stratigraphy and geochronology of the terrestrial dinosaur-bearing strata,i.e.,the Qiupa Formation,were poorly studied in the Luanchuan-Tantou Basin in western Henan,China.This study shows that these strata represent a complete succession from the Late Cretaceous to the early Paleogene,including the K/T boundary,in this area.Here we report a detailed study of the K/T boundary,especially its stratigraphic sequence,sedimentary characteristics,integrity,continuity,and geological implications.
JIANG XiaoJunLIU YongQingJI ShuAnZHANG XingLiaoXU LiJIA SongHaiLO JunChangYUAN ChongXiLI Ming
A new pterosaur Archaeoistiodactylus linglongtaensis gen. et sp. nov. is erected based on an incomplete skeleton with a partial skull and lower jaw. The new taxon is characterized by circular tooth sockets of anterior mandibular teeth,the anterior teeth of the upper jaw bearing posteriorly directed crowns,a relatively short metacarpus,and wing phalanges 2 and 3 and the tibia subequal in length. It possesses some plesiomorphic characters such as short metacarpals and circular tooth sockets. The pointed jaw tip present in the new taxon indicates that the expanded jaw tips of later istiodactylids are a derived character state,and the new taxon represents the first istiodactylus-like pterosaur found from the pre-Late Jurassic deposits,which provides a key role in our understanding the origin and evolution of the known istiodactylid pterosaurs. Archaeoistiodactylus is regarded as the ancestor form of the known istiodactylid pterosaur.
