Qianzhousaurus (meaning "Qianzhou lizard") is a genus of tyrannosaurid dinosaurs that lived in Asia during the Late Cretaceous period. There is currently only one species named, the type species Qianzhousaurus sinensis which is member of the tribe Alioramini within the group, and most closely related to Alioramus, another alioramin. There is currently only one species named, Qianzhousaurus sinensis. Nicknamed 'Pinocchio rex' for its long snout in comparison to other known tyrannosaurs, it convergently resembled spinosaurs. The animal was discovered in southern China in May 2014. Aside from its signature snout, it also had long, narrow teeth, while T. rex had thick teeth and powerful, deep-set jaws.
Discovery[]
Map showing the locality of the Ganzhou city, region where the holotype was discovered
The holotype specimen, GM F10004, was unearthed in southern China, Ganzhou, at the Nanxiong Formation in the summer of 2010 during the construction of an industrial park and it was first described by paleontologists Junchang Lü, Laiping Yi, Stephen L. Brusatte, Ling Yang, Hua Li and Liu Chen in the journal Nature Communications in 2014. The genus is known from a partial sub-adult individual consisting of a nearly complete skull with the lower jaws missing all teeth (lost during fossilization), 9 cervical vertebrae, 3 dorsal vertebrae, 18 caudal vertebrae, both scapulocoracoids, partial ilia, and the left hindlimb compromising the femur, tibia, fibula, astragalus with calcaneum, and metatarsals III and IV. The generic name, Qianzhousaurus, is in reference to Qianzhou (the older name of Ganzhou) where the remains were discovered, and the specific name, sinensis, is derived from the Greek Σῖναι (sin, sino, sinai) in reference to China. The fossil remains were discovered by workmen at a construction site near the city of Ganzhou, who then took them to a local museum.
Lead author Lü Junchang from the Institute of Geology, Chinese Academy of Geological Sciences stated that "the new discovery is very important. Along with Alioramus from Mongolia, it shows that the long-snouted tyrannosaurids were widely distributed in Asia. Although we are only starting to learn about them, the long-snouted tyrannosaurs were apparently one of the main groups of predatory dinosaurs in Asia." The existence of long-snouted tyrannosaurs was previously suspected due to other inconclusive fossil finds which could be explained as the juveniles of short-snouted species, but co-author Stephen L. Brusatte from the University of Edinburgh reveals that the find "tells us pretty unequivocally that these long-snouted tyrannosaurs were a real thing. They were a different breed, living right at the end of the age of dinosaurs."
Description[]
Life restoration
Qianzhousaurus was a medium-sized tyrannosaurid estimated to have been 6.3 m (21 ft) long and 757 kg (1,669 lb) in weight. The taxon can be differentiated from other tyrannosaurids in having a highly narrowed premaxilla, a pneumatic opening on the upper extension of the maxilla, and the lack of a vertical ridge-like structure on the lateral surface of the ilium.
Unlike more "traditional" tyrannosaurids, which had prominent deep-set jaws and thick teeth, Qianzhousaurus had a particularly elongated snout, with (when restored) narrow teeth. The holotype specimen is notably larger and more mature than the holotypes of both species of Alioramus; however, given that some sutures between the cervical and dorsal vertebrae are partially fused, the holotype was an immature animal, likely a sub-adult. Qianzhousaurus was a long-legged animal with a 70 cm (700 mm) long femur and 76 cm (760 mm) long tibia.
Large fenestra on the ascending ramus of the maxilla, a very reduced premaxilla, a laterally straight and rod-like nasal that does not expand at the naris, anteroventrally-oriented ventral process of the lacrimal, a shallow dorsal prong of the anterior ramus of thr squamosal, an anteroposteriorly-oriented ventral process of the squamosal, the anterior edge of the dentary smoothly merging with the ventral dentary margin and a highly concave dorsal margin of the supradentary are diagnosed as definate autapomorphies in a 2022 redescription. The same redescription finds possible yet problematic autapomorphies: an ovoid foramen on the medial of the prearticular and limited medial exposure of the coronoid in the medial.
Classification[]
Holotype skull diagram of A. remotus, which together with A. altai, form the closest relatives of Qianzhousaurus
The discovery of Qianzhousaurus led to a new branch of the tyrannosaur family being named, consisting of the long-snouted Q. sinensis and the two known species of Alioramus. This clade, named the Alioramini, had an uncertain placement relative to other members of the tyrannosaur branch in the initial analysis that discovered it. The primary phylogenetic analysis found Alioramini to be closer to Tyrannosaurus than to Albertosaurus, and therefore a member of the group Tyrannosaurinae. However, a second analysis in the same paper found it to be located outside of the clade including Albertosaurinae and Tyrannosaurinae, and therefore the sister group of Tyrannosauridae. Below is the first analysis found by the authors:
| Tyrannosauridae |
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Lü et al. (2014) recombined it as "Alioramus sinensis". In 2022, it was redescribed in detail and proven to be a valid taxon inside Alioramini. Foster et al. (2022) use this taxon to find lengthening of the anterior palate and the reflecting posterior bones in the mandible as giving alioraminins their characteristic elongate snouts, even though the posterior cranium is similar to proportionally similar deep-skulled tyrannosaurines.
Paleobiology[]
Qianzhousaurus (in blue) compared to other members of the Alioramini
Cranial morphology suggests a weaker bite that other deep-skulled tyrannosaurines that is likely analogous to a different prey preference and feeding style. The holotype was determined to be an adult and the nasal rugosities grew less prominent with age.
Paleoecology[]
Qianzhousaurus lived in the Nanxiong Formation in China and other parts of Asia during the Late Cretaceous period, around 72 to 66 million years ago. This site has yielded a diverse array of primitive and advanced oviraptosaurs, which would have been the main prey source for Qianzhousaurus. Other dinosaurs found here include the therizinosaur Nanshiungosaurus, the sauropod Gannansaurus and undescribed genera of hadrosaurs and larger tyrannosaurs. Research has shown that its jaws were best suited to preying on small dinosaurs and lizards, with experts suggesting that it was one of the most effective predators of its period.
Appearance in other media[]
Jurassic Park[]
- Qianzhousaurus appears in Jurassic World Evolution 2
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