Leptocleididae

Under construction

Skeleton of Brancasaurus in side view. From Sachs et al. (2016)

Skull of Brancasaurus in dorsal and lateral view, and showing the tip of the snout (C) in ventral view (from Wegner 1914)

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.

‘Gronausaurus‘ was named in 2013 (Hampe 2013). It is now regarded as a junior synonym of Brancasaurus (Sachs et al. 2016).

Under construction

Under construction

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.

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.