Qianosuchus possesed an elongated snout. The
rostrum formed by the
premaxilla is shallow at the front of the skull but deepens posteriorly. Each premaxilla has nine long teeth, and the
maxillae bear eighteen teeth each. All the teeth are laterally compressed, curved backwards and serrated, like those of most other carnivorous archosaurs. The
nares are expanded and elongated and almost collide with the
antorbital fenestrae, meaning that the septum (bony wall) between them is thin and lightweight. Unusually, the
jugal forms no part of the border of the antorbital fenestra. Each
orbit had a large and well-developed
scleral ring in it, which would have reinforced the eyeball under pressure when
Qianosuchus was diving. The
frontal bones have deep fossae (depressions) on their upper surface, which stretch backwards to the sutures with the
parietals. Another such fossa is present between the two parietals themselves. The
dentary turns down very slightly at the tip; a specimen described in 2023 shows that it possessed 22 teeth on each side of the lower jaw. The
hyoid bones are long and slender, with slightly expanded ends.
Qianosuchus had nine
cervical, fifteen
dorsal, two
sacral and more than fifty
caudal vertebrae with large neural spines, giving it an unusually long and expanded tail. The
neural spines grow taller posteriorly (further down the tail), making the caudal vertebrae tall. The first 23 caudal vertebrae have
transverse processes, but these processes are lost further back. The vertebral centra grow shorter posteriorly, making the tail more flexible than the neck. Many of the anterior caudal vertebrae have long
chevron bones ventral to them which also increase the height of the tail. The osteoderms are very small and numerous, and they are only present on top of the neck and torso, precluding their subsequent dissapearance in later poposauroids. The
cervical ribs are extremely elongate and thin, at least four times the length of their corresponding centra, and may have had strong muscles attached enabling it to create suction in its throat while lunging forward at prey by expanding the
oesophagus. The
dorsal ribs are expanded and
pachyostotic at their distal ends.
Qianosuchus'
scapulae were thin, and had an extremely broad dorsal blade. Its
coracoid bones were oval-shaped and quite thin, while its
clavicles articulated almost at right angles with the
interclavicle to form an L-shaped outline from the side. The forelimbs were slender and lightly built, and almost totally straight, and the specimen described in 2023 shows diminute metacarpals and manual phalanges The
pelvic girdle is similar to that of closely related but more terrestrial archosaurs, with the large posterior process and small anterior process on the
ilium, which also possesed a prominent crest of bone above the
acetabulum, characteristic of poposauroids. The
pubis had a deep foramen close to the proximal end, while the distal end of the thinner and shorter
ischium was slightly expanded. The
femur was weakly sigmoid, and the
fibula and
tibia were almost exactly the same length. The
calcaneum had a hemicylindrical condyle and a broad calcaneal tuber, while the
astragalus had a convex facet for the tibia. Five
metatarsals and two
tarsals are known, with the fifth metatarsal hooked, as in many other archosauromorphs. == Paleobiology ==