Open Paleo

Siluosaurus

Dong, 1997 suh-LOO-o-SAWR-us Nomen dubium

Named for the Silk Road (Chinese 'Silu'), referencing the discovery location in Gansu, China, along the historic Silk Road corridor, combined with Greek 'sauros' meaning 'lizard'; meaning 'Silk Road lizard.'

113.2–100.5 million years ago Albian, Early Cretaceous
Early Cretaceous stages

Siluosaurus is a genus of ornithischian dinosaur from the Early Cretaceous (Barremian-Albian) Xinminpu Group of Gansu, China, founded on two small teeth. The type species is S. zhangqiani.

Under dispute

Siluosaurus is a nomen dubium based on two isolated teeth from the Early Cretaceous of China. Dong (1997) named it as a hypsilophodontid — a now-abandoned grouping — and described the teeth as the smallest ornithopod teeth then known. It has since been treated as a dubious, tooth-based taxon (Butler and colleagues, 2008; Makovicky and colleagues, 2011), and Fonseca and colleagues (2024) found its teeth resemble those of both an ornithopod (Convolosaurus) and a ceratopsian (Archaeoceratops), placing it no more precisely than Cerapoda indeterminate.

Species

Siluosaurus zhangqiani Dong, 1997 Nomen dubium

Type species

Named in honor of Zhang Qian, a Chinese diplomat of the second century B.C. who pioneered the opening of the Silk Road trade route.

Holotype
IVPP V11117.1, IVPP V11117.2 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
Two small teeth, including a premaxillary tooth.
Horizon
Zhonggou Formation, Albian, Early Cretaceous , 113.2–100.5 million years ago
Locality
Gansu, China You and colleagues (2014) report that fieldwork in 2010 and 2011 confirmed the dinosaur-bearing Xinminpu Group of the Mazongshan area to be the Zhonggou Formation, citing a personal communication rather than a published section. Tang and colleagues (2001) instead divide the same strata into three informal units and place the area's hypsilophodontid material in the upper part of the Lower Red Unit.

References

  1. Dong, Z. (1997). A small ornithopod from Mazongshan area, Gansu Province, China. Sino-Japanese Silk Road Dinosaur Expedition 24-26. China Ocean Press, Beijing.

    Original description of Siluosaurus zhangqiani as a hypsilophodontid, based on two teeth from the Xinminpu Group.

    dong1997b
  2. Butler, R. J.; Upchurch, P.; Norman, D. B. (2008). The phylogeny of the ornithischian dinosaurs. Journal of Systematic Palaeontology 6(1): 1-40. doi:10.1017/S1477201907002271

    Excluded Siluosaurus from its ornithischian phylogeny as a questionable tooth-based taxon.

    butler2008b
  3. Makovicky, P. J.; Kilbourne, B. M.; Sadleir, R. W.; Norell, M. A. (2011). A new basal ornithopod (Dinosauria, Ornithischia) from the Late Cretaceous of Mongolia. Journal of Vertebrate Paleontology 31(3): 626-640. Informa UK Limited. doi:10.1080/02724634.2011.557114

    Treated Siluosaurus as a dubious tooth-based taxon.

    makovicky2011a
  4. Fonseca, A. O.; Reid, I. J.; Venner, A.; Duncan, R. J.; Garcia, M. S.; Müller, R. T. (2024). A comprehensive phylogenetic analysis on early ornithischian evolution. Journal of Systematic Palaeontology 22: 2346577. doi:10.1080/14772019.2024.2346577

    Found the teeth comparable to both ornithopods and ceratopsians and placed Siluosaurus no more precisely than Cerapoda indeterminate.

    fonseca2024a
  5. You, H. L.; Li, D. Q.; Dodson, P. (2014). Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. (Ornithischia: Hadrosauroidea) from the Early Cretaceous of Gansu Province, northwestern China. Hadrosaurs 73-76. Indiana University Press.

    Reports fieldwork in 2010 and 2011 confirming the dinosaur-bearing Xinminpu Group of the Mazongshan area as the Zhonggou Formation.

    you2014a
  6. Tang, F.; Luo, Z. X.; Zhou, Z. H.; You, H. L.; Georgi, J. A.; Tang, Z. L.; Wang, X. Z. (2001). Biostratigraphy and palaeoenvironment of the dinosaur-bearing sediments in Lower Cretaceous of Mazongshan area, Gansu Province, China. Cretaceous Research 22(1): 115-129. Elsevier BV. doi:10.1006/cres.2000.0242 tang2001b