Abyssosaurus nataliae is the type and only species of Abyssosaurus.
Thaumatodracon weidenrothi is the type and only species of Thaumatodracon. The species name honours Kurt Wiedenroth, the amateur fossil hunter who discovered and collected the specimen.
The holotype specimen (NHMUK PV R 1336) was first and last described by Owen, 1840. ‘Plesiosaurus’ macrocephalus is probably a juvenile rhomaleosaurid, and certainly doesn’t belong to the genus Plesiosaurus. However, pending revision of the taxon and referral to a different or other existing genus, it is still named ‘Plesiosaurus‘, following Owen.
Avalonnectes arturi is the type and only species of Avalonnectes.
R. thorntoni was first described briefly by Andrews (1922a). Smith and Benson (2014) described and figured R. thorntoni in detail in a monograph on the holotype specimen.
Mike Taylor studied the holotype of R. zetlandicus for his Ph.D. thesis and subsequently published a description of the cranial anatomy (Taylor, 1992). Vincent and Smith (2010) referred the holotype of R. propinquus to R. zetlandicus