Eonatator, STERNBERGII (WIMAN, 1920)

Bardet, Nathalie, Suberbiola, Xabier Pereda, Iarochene, Mohamed, Bouya, Baadi & Amaghzaz, Mbarek, 2005, A new species of Halisaurus from the Late Cretaceous phosphates of Morocco, and the phylogenetical relationships of the Halisaurinae (Squamata: Mosasauridae), Zoological Journal of the Linnean Society 143 (3), pp. 447-472 : 465

EONATATOR STERNBERGII ( WIMAN, 1920) COMB. NOV.

Holotype: UPI R 163 , a nearly complete skeleton described by Wiman (1920).

Type locality and horizon: Smoky Hill Member, Niobrara Chalk, Santonian (Late Cretaceous), Kansas ( USA).

Referred specimen: USNM 3777 , incomplete skeleton, Smoky Hill Member , Niobrara Chalk , Santonian ( Late Cretaceous ), Beaver Creek, Logan County, Kansas ( USA) ( Russell, 1967: 126) .

Emended diagnosis: Ambiguous characters: premaxilla–maxilla lateral suture ending posterior to the 9th maxillary teeth; tail about 40% of the head and trunk length (convergent in mosasaurines); caudal vertebra length greater than width; fewer than four pygal vertebrae; femur length about twice distal width (convergent in Clidastes ). Autapomorphies: parietal with smooth triangular table extending very far posteriorly, bearing medium-sized circular foramen, located at distance twice its diameter from the frontal–parietal suture, and surrounded anteriorly and posteriorly by two parallel ridges; rounded quadrate with regularly convex tympanic ala; vertebral formula: seven cervicals, 24 dorsals, four pygals, 28 median caudals and at least 41 terminal caudals; humerus length approximately 2.5¥ distal width.