Classification
Leptocleidids are derived plesiosauroids from the Cretaceous Period. They form a sister relationship with polycotylids.
Phylogeny
After Ketchum and Benson (2011)
Vectocleidus can be confidently identified as a leptocleidid but its position within the clade is unstable (Benson et al. 2012b).
Genera
Leptocleidus
Lower Cretaceous plesiosaurs are rare, so Leptocleidus is important because it fills a gap in the fossil record of plesiosaurians. Leptocleidus was once considered to be a late surviving member of the family Rhomaleosauridae but it has recently been reidentified as a close relative of polycotylids. The fossils of all known species of Leptocleidus were […]
Gronausaurus
‘Gronausaurus‘ was named in 2013 (Hampe 2013). It is now regarded as a junior synonym of Brancasaurus (Sachs et al. 2016). Under construction
Hastanectes
Under construction
Vectocleidus
The name Vectocleidus was erected by Benson et al. (2012b) for a leptocleidid from the Early Cretaceous of the Isle of Wight, UK. The type specimen was previously referred to Leptocleidus sp. Vectocleidus can be confidently identified as a leptocleidid but its position within the clade is unstable (Benson et al. (2012b).
Umoonasaurus
Umoonasaurus is a small (~2.5 m long) leptocleidid that lived during the Early Cretaceous in Southern Australia. The holotype specimen (AM F99374), a spectacular opalised skeleton including the skull, is nicknamed ‘Eric’. It is the most complete opalised plesiosaur skeleton (and fossil vertebrate) known. It was originally described briefly as Leptocleidus sp. by Kear (2006) […]

