However, the validity of Pythonomorpha is still debated; indeed, there is no consensus about the relationships of snakes or mosasaurs to each other, or to the rest of the lizards. An analysis by Conrad (2008) placed mosasaurs with varanoid lizards, and snakes with skinks, while an analysis by Gauthier et al. (2012) suggested that mosasaurs are more primitive than either snakes or varanoids. However, a combined morphological and molecular analysis by Reeder et al. (2015) recovered Mosasauria and Serpentes as sisters, consistent with Pythonomorpha.