Elasmosaurus Cope, 1869
Although Elasmosaurus is one of the most widely recognised plesiosaur names and has become a stereotype for all elasmosaurids, it is actually poorly known. Nothing is known of the limbs and most of the skull is unknown. The pectoral and pelvic girdles have been figured but the fossil material is missing and it is possible they have been destroyed (Carpenter, 1999). This is unfortunate because the pectoral girdle appears atypical for elasmosaurids in the retention of a pectoral bar and a long midline suture between the scaplae. Elasmosaurus has the largest number of vertebrae in any plesiosaur (72).
Many species of Elasmosaurus have been erected but the are all invalid or have been referred to new genera. Elasmosaurus platyurus is therefore the only valid species belonging to Elasmosaurus. The genus Libonectes was introduced by Carpenter (1997) for 'Elasmosaurus' morgani.
E. platyurus Cope, 1869
Type material: ANSP 10081, including the tip of the snout, occipital condyle and the majority of the cervical vertebrae. Pectoral and pelvic girdles now missing.
Referred material: None.
Age and Location
Sharon Springs Member (Lower Campanian), McAllister Butte, Pierre Shale, Logan County, Kansas, USA.