Dinosaur teeth from the mid-Cretaceous Sunjiawan Formation of western Liaoning Province, China

The mid-Cretaceous Sunjiawan Formation of western Liaoning Province, China has yielded a diverse of dinosaurs, yet without records of theropods. Recently, four isolated dinosaur teeth were discovered from the Sunjiawan Formation in Shuangmiao, Liangshuihe, Beipiao, Liaoning, China. They can be assigned to Tyrannosauroidea, Titanosauriformes and Hadrosauroidea based on morphological features. The tyrannosauroid tooth represents the first fossil record of Theropoda in the Sunjiawan Formation. The titanosauriform tooth is provisionally attributed to Borealosaurus considering that they are from the same horizon and locality. The hadrosauroid teeth represent a distinct taxon from Shuangmiaosaurus, the only known hadrosauroid from this formation. These findings increased the diversity of dinosaurs of the Sunjiawan Formation from three taxa to five.