Polyglyphanodontia

Tianyusaurus fossil

Reconstruction of Various Borioteiioidea. First row: Adamisaurus, Polyglyphanodon, Tuberocephalosaurus. Second row: Tianyusaurus, Gilmoreteius, Darchansaurus. Third row: Sineoamphisbaena.

A large-scale phylogenetic analysis of squamates conducted by Conrad (2008) found polyglyphanodontians (called Polyglyphanodontidae by Conrad) to be closely related to teiid lizards. In the strict consensus tree recovered in the analysis, polyglyphanodontids were part of a polytomy (unresolved evolutionary relationship) with teiids, gymnophthalmids, Chamops and lacertids; in the Adams consensus tree polyglyphanodontids were the sister group to teiids.[10] (Some other studies that recognize a close relationship between polyglyphanodontians and teiids use the name Borioteiioidea rather than Polyglyphanodontia, although Borioteiioidea encompasses only North American polyglyphanodontians.)[11] Conrad's analysis also recovered Sineoamphisbaena, a Cretaceous lizard that resembles legless amphisbaenian lizards, as a member of Polyglyphanodontidae.[10] On the other hand, a later large-scale phylogenetic analysis of fossil and living squamates published in 2012 by Gauthier et al. found that Polyglyphanodontia was not particularly closely related to teiids, but rather that it was the sister taxon of the clade containing the extinct marine mosasaurs, their closest relatives and the major lizard group Scleroglossa. Because the first scleroglossans appear in the Late Jurassic, polyglyphanodontians must also have originated in the Late Jurassic if this phylogeny is correct. However, polyglyphanodontians are limited to the Cretaceous, meaning that a long ghost lineage may exist.[7] The primary analysis of Gauthier et al. (2012) did not find polyglyphanodontians and Sineoamphisbaena to be closely related; however, the authors noted that when all snake-like squamates and mosasaurs were removed from the analysis, and burrowing squamates were then added individually to it, Sineoamphisbaena grouped with polyglyphanodontians. Gauthier et al. (2012) considered it possible that Sineoamphisbaena was a burrowing polyglyphanodontian,[7] though, agreeing with.[10] Subsequent analyses based on [10] have also supported Sineoamphisbaenia as a polyglyphanodontian (the combined molecular and morphological analysis of Müller et al.;[12] in the morphology only analyses carried out by Wiens et al. but not their combined molecular and morphological analyses;[13] and in morphology only analyses carried out by [14][15] who were describing new polyglyphanodontians from Asia [Funuisaurus and Tianyusaurus]).

A phylogenetic analysis conducted by Reeder et al. (2015) based on combined molecular and morphological data (based on [7]) recovered Polyglyphanodontia as members of Toxicofera; specifically, it was recovered as the sister group of Iguania.[16] Lee (2009)[17] analyzed a combined molecular and morphological data set (based on earlier studies by Lee[18][19]) and also had found polyglyphanodontians as the sister to iguanians but Lee's finding was not acknowledged by.[16] Combined molecular and morphological data analyses using Conrad's data [12][13] consistently found polyglyphanodontians as the sisters to teiioids.