Opinions from S. P. Welles 1943

  • 'Alzadasaurus belongs to Elasmosauridae'
  • 'Alzadasaurus riggsi belongs to Alzadasaurus'
  • 'Aphrosaurus belongs to Elasmosauridae'
  • 'Aphrosaurus furlongi belongs to Aphrosaurus'
  • 'Brimosaurus is a nomen dubium'
  • 'Brimosaurus grandis is a nomen dubium'
  • 'Cimoliasaurus is a nomen dubium'
  • 'Cimoliasaurus magnus is a nomen dubium'
  • 'Discosaurus carinatus is an objective synonym of Elasmosaurus platyurus'
  • 'Elasmosauridae belongs to Plesiosauroidea'
  • 'Elasmosaurus belongs to Elasmosauridae'
  • 'Elasmosaurus marshii is recombined as Thalassonomosaurus marshii'
  • 'Elasmosaurus nobilis is recombined as Thalassonomosaurus nobilis' according to Williston 1906
  • 'Elasmosaurus nobilis is recombined as Thalassonomosaurus nobilis'
  • 'Elasmosaurus platyurus belongs to Elasmosaurus'
  • 'Elasmosaurus serpentinus is recombined as Hydralmosaurus serpentinus'
  • 'Elasmosaurus sternbergi is a nomen dubium'
  • 'Fresnosaurus belongs to Elasmosauridae'
  • 'Hydralmosaurus belongs to Elasmosauridae'
  • 'Hydrotherosaurus belongs to Elasmosauridae'
  • 'Hydrotherosaurus alexandrae belongs to Hydrotherosaurus'
  • 'Leurospondylus belongs to Elasmosauridae'
  • 'Morenosaurus belongs to Elasmosauridae'
  • 'Morenosaurus stocki belongs to Morenosaurus'
  • 'Plesiosauridae belongs to Plesiosauroidea'
  • 'Plesiosauroidea belongs to Plesiosauria'
  • 'Pliosauridae belongs to Pliosauroidea'
  • 'Pliosauroidea belongs to Plesiosauria'
  • 'Polycotylidae belongs to Pliosauroidea'
  • 'Polycotylus ischiadicus is recombined as Thalassiosaurus ischiadicus'
  • 'Styxosaurus belongs to Elasmosauridae'
  • 'Thalassiosaurus belongs to Elasmosauridae'
  • 'Thalassomedon belongs to Elasmosauridae'
  • 'Thalassomedon hanningtoni belongs to Thalassomedon'
  • 'Thalassonomosaurus belongs to Elasmosauridae'