Metal & Mosasaurs 🤘🦎 : History Museum at the Castle : @RGGSatAMNH : @SkeleCrewPaleo Co-Founder : NSFGRFP Fellow : she/her 🖤🤍💜 : views my own
We know that mosasaurs are lizards, & everyone agrees that within lizards, they're non-iguanian toxicoferans. Beyond that, however, there are 2 leading hypotheses: mosasaurs are either most closely related (1) snakes OR (2) monitor lizards. The root cause of this ambiguity... 
Perhaps unsurprisingly, properly identifying & diagnosing extinct species is incredibly tricky! For starters, because they are, necessarily, dead & gone, we cannot use many of the same species concepts we use for living animals (e.g., whether individuals interbreed)
First, let's talk about the new kid on the taxonomic block: Thalassotitan! It belongs to a group of mosasaurs called Prognathodontini, all bruisers with insanely powerful jaws & massive, serrated conical teeth - NOT adaptations for making friends!