Polrussia

Polrussia Temporal range:Late Cretaceous
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Iguania
Clade:	†Gobiguania
Genus:	†Polrussia Borsuk-Białynicka and Alifanov,1991
Type species
†Polrussia mongoliensis Borsuk-Białynicka and Alifanov, 1991

Polrussiais an extinctgenusofiguanianlizardsdating to theLate Cretaceousepoch, found in what is now Mongolia. It belongs to a group of extinct iguanians calledGobiguaniathat was endemic to theGobi Desertduring the Late Cretaceous. Thetype speciesPolrussia mongoliensiswas named in 1991 on the basis of a skull found in theBarun Goyot Formation.The genus name refers to the Polish and Russian paleontologists who worked together to find and describe the material.Polrussiahas a short skull, slightly pointed and flattened snout, and large eye sockets. The teeth each have one cusp, as opposed to the multiple cusps seen in some other gobiguanians. The skull is only 1.2 centimetres (0.47 in) long, makingPolrussiaone of the smallest gobiguanians.

Below is acladogramfrom Dazaet al.(2012) showing the phylogenetic relationships ofPolrussia:

Iguania

†Hoyalacerta sanzi †Huehuecuetzpalli mixtecus †Pristiguana brasiliensis Chamaeleontiformes †Priscagamidae Acrodonta Iguanoidea(=Pleurodonta) Silvaiguana Hoplocercidae Polychrotidae †Gobiguania †Polrussia mongoliensis †Igua minuta †Isodontosaurus gracilis †Anchaurosaurus gilmorei †Zapsosaurus sceliphros †Saichangurvel davidsoni †Temujinia ellisoni †Ctenomastax parva Euiguana Corytophanidae Terraiguana Iguanidae Crotaphytidae Phrynosomatidae Opluridae †Uquiasaurus Liolaemidae Leiocephalus Tropiduridae