Phaanthosaurus is an extinct genus of basal procolophonid parareptile from early Triassic (Induan stage) deposits of Nizhnii Novgorod, Russian Federation. It is known from the holotype PIN 1025/1, a mandible (a dentary). It was collected from Vetluga River, Spasskoe village and referred to the Vokhmian terrestrial horizon of the Vokhma Formation. It was first named by P. K. Chudinov and B. P. Vjushkov in 1956 and the type species is Phaanthosaurus ignatjevi.[1][2]

Temporal range: Early Triassic, Induan
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Parareptilia
Order: Procolophonomorpha
Family: Procolophonidae
Genus: Phaanthosaurus
Chudinov & Vjushkov, 1956
  • P. ignatjevi Chudinov & Vjushkov, 1956 (type)
  • P. simus (Ivakhnenko, 1974)
  • Contritosaurus simus Ivakhnenko, 1974
  • C. convector Ivakhnenko, 1974

In 2000, Spencer and Benton found Contritosaurus to be junior synonym of Phaanthosaurus. C. simus Ivakhnenko, 1974 which is known from the holotype PIN 3355/1, a partial skull with right mandible from the same location, and from three paratypes, was recombined as P. simus. They also found that the second species of Contritosaurus, C. convector (PIN 3357/1, a mandible) is a junior synonym of P. simus.[3] Recent cladistic analyses by Juan Carlos Cisneros, 2008 and Mark J. Macdougall and Sean P. Modesto, 2011 accepted this synonymy.[4][5]


  1. ^ P. K. Chudinov and B. P. Vjushkov (1956). "New Data on Small Cotylosaurs from the Permian and Triassic of the USSR". Doklady Akademii Nauk SSSR. 108 (3): 547–550 [In Russian].{{cite journal}}: CS1 maint: uses authors parameter (link)
  2. ^ Ivakhnenko, M. F. (1974). "New data on Early Triassic procolophonids of the USSR". Paleontological Journal. 8: 346–351.{{cite journal}}: CS1 maint: uses authors parameter (link)
  3. ^ P. S. Spencer & M. J. Benton (2000). "Procolophonids from the Permo-Triassic of Russia". In M. J. Benton; M. A. Shishkin; D. M. Unwin & E. N. Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia. Cambridge: Cambridge University Press. pp. 160–176. ISBN 9780521554763.
  4. ^ Juan Carlos Cisneros (2008). "Phylogenetic relationships of procolophonid parareptiles with remarks on their geological record". Journal of Systematic Palaeontology. 6 (3): 345–366. doi:10.1017/S1477201907002350. S2CID 84468714.{{cite journal}}: CS1 maint: uses authors parameter (link)
  5. ^ Mark J. Macdougall and Sean P. Modesto (2011). "New information on the skull of the Early Triassic parareptile Sauropareion anoplus, with a discussion of tooth attachment and replacement in procolophonids". Journal of Vertebrate Paleontology. 31 (2): 270–278. doi:10.1080/02724634.2011.549436. S2CID 84934974.{{cite journal}}: CS1 maint: uses authors parameter (link)