Dallasaurus turneri, a new primitive mosasauroid from the Middle Turonian of Texas and comments on the phylogeny of Mosasauridae (Squamata)

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.

In Bell and Polcyn's sampled analysis, Mosasauridae includes plesiopedal Dallasaurus as well as more derived hydropedal members, so limb grade alone is not treated as a family diagnosis.

The 92–66 Ma Mosasauridae display is a two-study sampled envelope: two Dallasaurus skeletons document a middle Turonian (~92 Ma) occurrence, and Mosasaurus hoffmanni NHMM 2007 093 occurs within one metre below the regional K/Pg boundary; neither edge is an exact global family FAD or LAD.

The profile's geographic examples are restricted to middle Turonian Dallasaurus skeletons from north-central Texas and latest-Maastrichtian Mosasaurus hoffmanni NHMM 2007 093 from the Maastricht type area; they are not a complete Mosasauridae distribution map.

The two incomplete Dallasaurus skeletons preserve cranial, axial and plesiopedal limb characters, and the cited analysis places that condition within Mosasauridae alongside independently acquired hydropedal limbs; this is a character-and-topology result, not a linear ancestor-to-descendant sequence.

Bell and Polcyn distinguish small plesiopedal from larger hydropedal adaptive grades, while tooth-enamel carbon isotopes from five type-Maastrichtian mosasaur taxa support marine carnivory and resource partitioning; these samples do not establish one family-wide diet, foraging habitat, swimming mode or body size.

Dallasaurus turneri from the middle Turonian Arcadia Park Shale supports a 93.9–89.8 Ma named mosasauroid sample window; it does not establish a global Mosasauroidea FAD or LAD.

The profile's named mosasauroid samples include Dallasaurus turneri from the middle Turonian Arcadia Park Shale of north-central Texas and a latest Maastrichtian Mosasaurus occurrence from the Maastricht type area of the Netherlands; these records do not establish a global Mosasauroidea distribution.

Dallasaurus preserves cranial, axial and plesiopedal limb anatomy in two incomplete skeletons, while the cited nomenclatural analysis distinguishes the broader Mosasauroidea branch from node-defined Mosasauridae; limb grade is not treated as the clade definition.

Schulp et al. report tooth-enamel carbon-isotope, body-size and resource-partitioning results for five named mosasaurs in one type-Maastrichtian fauna; the study-bounded marine sample does not establish a single diet, body-size distribution or guild for all Mosasauroidea.