Open Paleo

Shanyangosaurus

Xue et al., 1996 shahn-yahng-o-SAWR-us

Named after the Shanyang Formation (Shanyang County, Shaanxi, China) where it was found, combined with Greek sauros, "lizard" — means "Shanyang lizard"

Shanyangosaurus is a genus of theropod dinosaur found in Shaanxi, China, and known only from a partial sacrum, partial scapula, humeri, femur, tibia, metatarsals, and phalanges found in the Late Cretaceous Shanyang Formation. The bones are reportedly hollow; this, along with other features of the femur and known foot bones, suggest it is a member of the coelurosauria, but a specific family cannot be determined without more material. Holtz and colleagues assigned Shanyangosaurus to Avetheropoda.

Under dispute

Shanyangosaurus niupanggouensis is known from a partial postcranium and is poorly constrained. It has been assigned to Avetheropoda (Holtz and colleagues, 2004) and, in a more recent analysis, recovered as a basal oviraptorosaur close to Caudipteryx (Hartman and colleagues, 2019), though that result is regarded as far from definitive. It is placed conservatively at Avetheropoda incertae sedis.

Diagnosis

  1. Femur lacking a fourth trochanter
  2. Femur distinctly curved anteriorly, relatively short, with a deep, wide intercondylar groove at the distal end
  3. Tibia slender and twisted, with an elongated, flattened cnemial crest and a flattened distal end lacking deep grooves
  4. Lesser trochanter of the femur in the form of a narrow ridge, with a small, shallow caudofemoral attachment scar lacking distinct margins
  5. Tibia longer than the femur (ratio about 126%) and the metatarsus greatly elongated (about 53% of femur length)

Species

Shanyangosaurus niupanggouensis Xue et al., 1996

Type species

Named for Niupanggou, the locality in Shaanxi, China where the fossils were discovered.

Holotype
NWUV 1111 , Northwest University
Material
Thoracic elements, the left scapula, both humeri, the sacrum, right femur, right tibia, both fourth metatarsals, several phalanges, and a claw.
Horizon
upper Shanyang Formation, Late Cretaceous
Locality
Niupanggou, Shaanxi, China Xue and colleagues (1996) give the holotype's locality and horizon as "Niupanggou, Shanyang, Shaanxi; upper part of the Upper Cretaceous Shanyang Formation", with no stage. The Maastrichtian appears only in reference works, Holtz and colleagues (2004) placing the genus "from the Maastrichtian", and not in the naming paper.

References

  1. Xue, X.; Zhang, Y.; Bi, Y.; Yue, L.; Chen, D. (1996). The development and environmental changes of the intermontane basins in the eastern part of Qinling Mountains. Geological Publishing House, Beijing. xue1996a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the body length estimate.

    jones2026c
  3. Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247. PeerJ. doi:10.7717/peerj.7247

    Recovered Shanyangosaurus as a basal oviraptorosaur near Caudipteryx.

    hartman2019a
  4. Holtz, T. R.; Molnar, R. E.; Currie, P. J. (2004). Basal Tetanurae. The Dinosauria, Second Edition (Weishampel, D. B.; Dodson, P.; Osmólska, H., eds.) 71-110. University of California Press, Berkeley.

    Assigned Shanyangosaurus to Avetheropoda incertae sedis.

    holtz2004a