nhmuk 49202 possesses plesiomorphic characters, including premaxillae that do not separate the frontals on the midline, narrow cranioquadrate passages and the lack of a constricting groove around the occipital condyle. it also shows several autapomorphies not observed in other plesiosaurians. its posteromedial processes of the premaxillae (or possible anterior portion of the frontal) forming a dorsoventrally thick, mediolaterally expanded platform and its cultriform process of the parasphenoid is wider mediolaterally than the combined posterior interpterygoid vacuities. it also has two closely spaced foramina in the lateral surface of the exoccipital. additional autapomorphies are the presence of supplementary foramen penetrating the parietal sagittal crest, the absence of a pterygoid-vomerine contact and the absence of a contact between the pterygoids in palatal aspect. a phylogenetic analysis performed by benson "et al." (2012) found it to be a basal, non-neoplesiosaurian, plesiosaur. the cladogram below shows "anningasaura" phylogenetic position among other plesiosaurs following benson "et al." (2012).