Estesia

Estesia mongoliensis (Dashzeveg et al., 1995), is a Late Cretaceous varanid similar to bothVaranus and Heloderma. The dentition indicates that Estesia delivered venom. Norell and Keguin (1997) found a sisterhood with Heloderma. The erected the clade Monstersauria to include Estesia and Heloderma.

Here Estesia was derived from a sister to Bahndwivici and phylogenetically preceded Varanus and Aigialosaurus.Ardeosaurus and most snake relatives were related. Heloderma nested elsewhere.

Dashzeveg DM, Novacek J, Norell MA, Clark JM, Chiappe, Davidson A, MeKenna MC, Dingus L, Swisher C ,and Altangerel P 1995. Extraordinar ypreservation in a new
vertebrate assemblage from the Late Cretaceous of Mongolia. Nature 374: 446-449.

Norell MA and Keguin G 1997. Braincase and Phylogenetic Relationships of Estesia mongoliensis from the Late Cretaceous of the Gobi Desert and the Recognition of a New Clade of Lizards*. American Museum Novitates 3211: 25pp.

Scleroglossa

Gekko

Anguimorpha

Carusia