The positive type specimens of Siamiaurus are several teeth. These teeth are cone-shaped with many longitudinal ridges and gullies. Although some post-head skeletal material is thought to belong to Siamosaurus, its taxonomic status has been disputed. It is generally believed that Siamosaurus belongs to the spinosaurus group because it has teeth similar to those of the heavy-clawed dragon, and some materials of the back bone also indicate that it may have tail sails to assist swimming. But there are other ideas that it's not a dinosaur at all.

It is a large spinosaurus found in Africa. It is estimated that it can reach 12 meters in length and weigh about 3 tons. At present, there is only one species under this subordinate, namely, the model species Tenere resembles a crocodile. Compared with other spinosaurus, the skeleton of the alligator is relatively intact, making it one of the most clearly studied spinosaurus. The crocodile-like dragon has a long, narrow skull and dense, conical teeth. The vertebral nerve spines of the alligator-like dragon are somewhat extended in the dorsal abdomen, but are not as exaggerated as those of the spinosaurus, and may also support the structure of the dorsal sail like that of the spinosaurus.

Jilong is a medium-sized spinosaurus, whose fossils were discovered in Brazil during the Early Cretaceous period. At present, there is only one species under the genus Jilong, which is the type species Chalinjie Jilong. Fossil materials of Jilong are also very rare, but what is slightly better than other similar specimens is that the holotype specimen of Jilong is a well preserved skull. Although the snout is missing, the latter half of the mouth and skull are preserved, which can provide more information for phylogenetic analysis and other research.