"Sinopliosaurus" is a spinosaurid theropod dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

 from the Early Cretaceous

Early Cretaceous

The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

 of southern China

Northern and southern China

Northern China and southern China are two approximate regions within China. The exact boundary between these two regions has never been precisely defined...

, known only from teeth. It includes a single species, "S." fusuiensis, that was first assigned to the plesiosaur

Plesiosaur

Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

 Sinopliosaurus

Sinopliosaurus

Sinopliosaurus is a genus of pliosauroid plesiosaur, a type of short-necked marine reptile, from the Early Cretaceous of People's Republic of China. One species, "S." fusuiensis, was later shown to be based on teeth from a spinosaurid theropod dinosaur....

. Because this species is not a plesiosaur and therefore is not within the genus Sinopliosaurus, the name "Sinopliosaurus" is used in quotation marks. The teeth came from an animal similar to Siamosaurus

Siamosaurus

Siamosaurus is a genus of theropod dinosaur from Early Cretaceous Thailand. The size of the animal is unknown, but it may have reached a length of about 9.1 meters . The type species, Siamosaurus suteethorni, was formally described by Buffetaut and Ingavat in 1986...

.