Elasmosaurid plesiosaur possessing the following unique combination of character states: interclavicle rectangular with rounded corners and possessing a notch along either the anterior or posterior margin (orientation to be confirmed upon discovery of articulated material); ventral ramus of scapula reaches midline but lacks a broad contact with its opposite; scapula with a prominent posteriorly directed prong extending toward the coracoid; well-developed midline contact between scapula and coracoid (pectoral bar) present in adult; presence of a well-developed anterior process of the coracoid along the midline, contributing extensively to the pectoral bar; coracoid of adult with a very prominent, ventrally extending midline process; cordiform intercoracoid vacuity fully enclosed posteriorly by coracoids; humerus with a pronounced postaxial accessory facet.

Matronym in memory of Elizabeth ("Betsy") Nicholls, curator of marine reptiles at the Royal Tyrrell Museum of Palaeontology, for her enduring influence on research in Mesozoic marine vertebrates (gender; feminine).