In Depth
In 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.
Further Reading
- 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.
