A Review of Non-Mosasaurid (Dolichosaur and Aigialosaur) Mosasaurians and Their Relationships to Snakes

A New Species of the Pythonomorph Carentonosaurus from the Cenomanian of Algora (Guadalajara, Central Spain)

“…The phylogenetic relationships between the non-ophidian, non-mosasaurid pythonomorphs are not agreed upon (see Augusta et al [ 68 ]). While some authors propose the clade Ophidiomorpha (i.e., ‘dolichosaur’-like taxa + Ophidia) [ 36 , 37 ], others consider the clade Mosasauria (i.e., ‘dolichosaur’-like taxa + Mosasauroidea) [ 13 , 68 , 69 , 70 ].…”

“…The phylogenetic relationships between the non-ophidian, non-mosasaurid pythonomorphs are not agreed upon (see Augusta et al [ 68 ]). While some authors propose the clade Ophidiomorpha (i.e., ‘dolichosaur’-like taxa + Ophidia) [ 36 , 37 ], others consider the clade Mosasauria (i.e., ‘dolichosaur’-like taxa + Mosasauroidea) [ 13 , 68 , 69 , 70 ]. Within the non-ophidian, non-mosasaurid pythonomorph representatives, the following can be excluded from further comparisons with the Algora specimen for lacking pachyostotic s.l.…”

Jormungandr walhallaensis: A New Mosasaurine (Squamata: Mosasauroidea) from the Pierre Shale Formation (Pembina Member: Middle Campanian) of North Dakota

“…While we do agree that the use of an artificial composite outgroup is flawed, we do not think that the total exclusion of anguimorph outgroups as done by Simões et al (2017) and nearly all other analyses of mosasaur phylogeny since is warranted because the character states were originally conceived and polarized using Anguimorpha as the point of reference (Bell, 1997). Furthermore, in contrast to the second point made by Simões et al (2017), use of anguimorph lizards as the outgroup to Mosasauroidea is justified given the recent placement of mosasauroids as sister to varanoids based on morphological and molecular datasets (Augusta et al, 2022;Polcyn et al, 2022).…”

“…Mosasaurs are an extinct lineage of squamate reptiles that reigned as apex marine predators of oceans and waterways globally during the Late Cretaceous (98 to 66 mya; Polcyn et al, 2014). Although their exact position within Squamata has long been contested (e.g., Russell, 1967; Carroll and DeBraga, 1992; Lee, 1997; Rieppel and Zaher, 2001; Gauthier et al, 2012; Reeder et al, 2015; Simões et al, 2017) and will likely not be irrefutably settled for some time, they are generally recovered within Toxicofera, and the most recent analyses using both morphological and molecular data have recovered Mosasauroidea as sister to Varanoidea (Augusta et al, 2022; Polcyn et al, 2022). Within Mosasauroidea, three major lineages of derived mosasaurs are recognized: Tylosaurinae, Plioplatecarpinae, and Mosasaurinae (Russell, 1967; Polcyn and Bell, 2005; Palci et al, 2013).…”