Explicit phylogenetic definitions separate broad Mosasauroidea from node-defined Mosasauridae, while Dallasaurus shows that family placement need not imply fully paddle-like limbs.
Represented range100.5–89.8 Ma
RegionsCretaceous mosasauroid records; middle Turonian of north-central Texas
Mosasauroidea and Mosasauridae are not interchangeable: the former is a broader branch-defined mosasauroid clade, whereas the latter is a node-defined family; Dallasaurus anatomy shows that family placement and fully paddle-like limb specialization are separate character questions.