Two new plioplatecarpine mosasaurs (Mosasauridae; Plioplatecarpinae) of the genus Ectenosaurus from the Upper Cretaceous of North America Author Kiernan, Caitlin R. Author Ebersole, Jun A. text PaleoBios 2023 2023-10-23 40 13 1 28 http://dx.doi.org/10.5070/p9401362375 journal article 10.5070/P9401362375 0031-0298 EE96562A-AEB9-4E4C-AAAF-036F41D8D3EF PLIOPLATECARPINAE DOLLO, 1884 Diagnosis (after Konishi and Caldwell 2011 )― Russellosaurines generally of medium size, mandible length rarely reaching 100 cm ; quadrate ala laterally expanded with uniformly curved border, thin in the center; distinct alar concavity present immediately dorsal to mandibular condyle;surprastapedial process elongate, at least reaching mid-height of quadrate; process often ending with blunt terminus; canal(s) for basilar artery through basisphenoid and basioccipital exiting as large opening(s) on medullary floor; jaws slender; a large foramina on lateroventral/ventral face of retroarticular process; marginal tooth crowns slender, distally tapering and posteromedially recurved from mid-height; middle and posterior tooth crowns typically bicarinate, two carinae aligned in anteroposterior orientation and dividing crown surface semi-equally; marginal tooth crown medially finely striated, laterally faceted or fluted to various extent;tooth crown with sub-circular basal cross-section; intermediate and terminal caudal centra horizontally short, centrum length not exceeding centrum height more than 1.5 times. Included Genera— Platecarpus Cope (1869) , Plioplatecarpus Dollo (1882) , Goronyosaurus Azzaroli et al. (1972) , Angolasaurus Antunes (1964) , Ectenosaurus Russell (1967) ; Selmasauru s Wright and Shannon (1988) , Russellosaurus Polcyn and Bell (2005) , Latoplatecarpus Konishi and Caldwell (2011) , Plesioplatecarpus Konishi and Caldwell (2011) , Gavialimimus Strong et al. (2020) , and Sarabosaurus dahli Polcyn et al. (2023) .