Chilantaisaurus

Chilantaisaurus (" lizard") is an extinct genus of large theropod dinosaur that lived in present-day China during the Late Cretaceous period. It was described by Chinese paleontologist Hu Show-Yung in 1964. The genus contains a single valid species, C. tashuikouensis, though several other species have been assigned to the genus. C. tashuikouensis is known from a single, incomplete postcranial skeleton, the holotype specimen. This specimen was found by a joint Sino-Soviet expedition to Inner Mongolia in rock layers coming from the Ulansuhai Formation. This indicates these fossils date to the Santonian or Campanian stages of the Cretaceous period, around 85.7 to 72.2 million years ago. However, the age of the Ulansuhai Formation is debated.

Chilantaisaurus was around in length and weighed . This makes it among the largest known theropod genera, comparable to Tyrannosaurus. The forelimbs of Chilantaisaurus are only known from a humerus and a manual ungual (hand claw); this humerus is one of the largest humeri known from a theropod dinosaur. It measures in length and has a greatly expanded . The ratio between the humerus and femur length is very high, in contrast to those of carcharodontosaurids like Mapusaurus but comparable to those of spinosaurids like Suchomimus. The hindlimbs were long with a robust metatarsus, unlike that of its possible relative Australovenator.