Named By: Young - 1942.
Synonyms: S. yandonensis.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, Theropoda, Neotheropoda.
Species: S. campi (type).
Size: Unknown due to lack of skeletal remains.
Known locations: China - Dashanpu (Shangshaximiao) Formation.
Time period: Oxfordian/Kimmeridgian of the Jurassic.
Fossil representation: Teeth.
modern times Szechuanosaurus is widely regarded as
a dubious genus
because it has only been described from a collection of isolated
teeth. Also, because these teeth do not really have any
specifically characteristic features, it is highly unlikely that
skeletal remains could be later attributed to these teeth (like what
happened with Troodon).
With the teeth officially described as
indeterminate, Szechuanosaurus will continue to
be called a ‘tooth
taxon’ that represents an unknown theropod, that may actually
already have been described, but we can never know for certain.
There has however been past attempts to assign post cranial remains to the teeth of Szechuanosaurus. A partial skeleton first described in 1978 (Dong et al) as Szechuanosaurus "yandonensis" was officially assigned to the type species S. campi in 1983. However a 2012 study (Carrano, Benson & Sampson) has now placed these remains within Yangchuanosaurus shangyouensis, another theropod from the Dashanpu Formation, but one that is a lot better represented by fossils. Remains of a third species, S. zigongensis, were also attributed to Yangchuanosaurus at this time.
Because only teeth are known for Szechuanosaurus it is impossible to infer anything beyond that it has a theropod and a meat eater. Hailing from the Dashanpu Formation however it did live alongside many other theropods, assuming that the teeth do not actually belong to any of these genera of course. As of 2012 and aside from Yangchuanosaurus these other genera also include Sinraptor, Chuandongocoelurus, Kaijiangosaurus, Gasosaurus, Leshansaurus and Xuanhanosaurus. Possible prey dinosaurs of all of these theropods could include ornithopods like Agilisaurus, stegosaurs like Chialingosaurus and Huayangosaurus as well as sauropods such as Datousaurus and Mamenchisaurus.
- The phylogeny of Tetanurae (Dinosauria: Theropoda), M. T. Carrano, R. B. J. Benson & S. D. Sampson - 2012.
- [The dinosaurian remains of Sichuan Basin, China]. Palaeontologica Sinica, Z-M Dong, S. Zhou & Y. Zhang - 1983.
- A new species of Szechuanosaurus from the Middle Jurassic of Dashanpu, Zigong, Sichuan. - Vertebrata PalAsiatica 31(4): 308-314. - Y. Gao - 1993.