Review of historical and current research on the Late Cretaceous dinosaurs and dinosaur eggs from Laiyang, Shandong

摘要: Here we briefly review the history of research on the Laiyang dinosaur and dinosaur egg faunas, summarize the contributions of C. C. Young and other elder paleontologists to the discoveries of the Late Cretaceous dinosaurs and dinosaur eggs from Laiyang, and introduce the new discoveries and the advances in the research on the Laiyang faunas. The new investigations in Laiyang from 2008 have found a series of valley developed in plain and more than ten new dinosaur or dinosaur egg fossil beds. In 2010, we began the massive excavations at two localities in Jingangkou and collected abundant dinosaurs and other vertebrate fossils, such as a new saurolophine, some theropod material and a new taxon of turtle egg. The bone beds in Locality 2 with the typical sedimentary and burial patterns of mudflow, and these fossil deposits are interpreted as having been carried and deposited by mudflow. The re-observation and the CT scanning data of the crest of Tsintaosaurus spinorhinus (IVPP V 725) show that the crest is fractured and solid. However, based on the re-observations of its cranial and postcranial specimens, we consider that Tsintaosaurus spinorhinus is a valid taxon of lambeosaurines, which have the hollow crest. Therefore, the crest of Tsintaosaurus might not belong to the skull of this individual, and the true form of the crest needs to be confirmed in the future work. We reassess the three species of Tanius, and obtain several results. 1) Tanius sinensis and Tanius chingkankouensis are the valid species of Tanius; 2) Tanius laiyangensis is invalid.; 3) the sacrum and ilium of Tanius chingkankouensis with typical hadrosaurid features should not be referred to Tanius.