Incisivosaurus ("incisor lizard") is a genus of small, probably herbivorous theropod dinosaurs from the early Cretaceous Period of what is now the People's Republic of China.

The first specimen to be described (by Xu et al. in 2002), IVPP V13326, is a skull that was collected from the lowermost levels (the fluvial Lujiatun beds) of the Yixian Formation (dating to the Barremian stage about 126 million years ago[1]) in the Sihetun area, near Beipiao City, in western Liaoning Province.

It was named for its prominent, rodent-like front teeth, which show wear patterns commonly found in plant-eating dinosaurs.

[2] The initial description of Incisivosaurus by Xu et al. showed that the skull, which measures approximately 10 cm (3.9 in) in length, preserves the most complete dentition known for any oviraptorosaurian.

Their cladistic analysis indicated that Incisivosaurus lies at the base of the oviraptorosaurian group, making it more primitive than Caudipteryx and the oviraptorids.

In addition to these unique features, Incisivosaurus shared many traits with more typical oviraptorosaurs, allowing its classification with that group.

[7] Additionally, the youngest specimen's vaned feathers appeared to lack barbs except at the tip, instead consisting of a solid sheet.

[10] Incisivosaurus, as well as its potential synonym Protarchaeopteryx, were included in the phylogenetic analysis of a 2014 study on the group Paraves and its relatives.

The moderate jaw gape seen in oviraptorosaurs is indicative of herbivory, but it is clear they were feeding on much tougher vegetation than other herbivorous theropods in their environment, such as ornithomimosaurs and therizinosaurs.

The examinations suggest oviraptorosaurs may have been powerful-biting generalists or specialists that partook of niche partitioning both in body size and jaw function.