Opallionectes
Opallionectes is a large, around 5 m long, derived cryptoclidid plesiosauroid from the Early Cretaceous of South Australia. It is known from a partial opalised skeleton, which is mounted for display in the South Australian Museum. The holotype specimen lacks a skull. It is diagnosed by the following unique combination of characters: small needle-like teeth with a distinct ovoid cross-section...
Plesionectes
Under construction...
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) who figured the skull and...
The Return of the Blockley Plesiosaur
In summer 2023 a plesiosaur skeleton was offered at auction by Sotheby’s that may have looked familiar. This notable specimen is the ‘Blockley Plesiosaur’, originally offered at auction by Sotheby’s in 2010. This is a potentially significant specimen so I’m flagging it up to briefly discuss the provenance, history, and taxonomic identity of this curious skeleton. The Blockley Plesiosaur 2,...
Nakonanectes
Nakonanectes is a small elasmosaurid plesiosaur from the Bearpaw Shale of Montana, USA. It is known from a single moderately complete specimen including a particularly fine skull. It has a relatively short neck for an elasmosaur consisting of ‘only’ 39-42 neck vertebrae. However, 16–19 of the neck vertebrae were lost in a “heavy spring runoff that occurred between the time...
Woolungasaurus
Sachs (2004) regarded ‘Woolungasaurus‘ as a junior synonym of Styxosaurus and assigned the type species (‘W. glendowerensis‘) to that genus under the new combination ‘Styxosaurus glendoweresnis‘. However, this placement was unsupported by unambiguous apomorphic characters (Kear 2007). Since ‘Woolungasaurus‘ has no unique diagnostic characters, Kear (2005) reassigned all specimens of it to Elasmosauridae indet. (indeterminate elasmosaurid). The genus ‘Woolungasaurus‘ is...
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). Vectocleidus material on display in the Dinosaur Isle...
Gronausaurus
‘Gronausaurus‘ was named in 2013 (Hampe 2013). It is now regarded as a junior synonym of Brancasaurus (Sachs et al. 2016). Under construction...
Colymbosaurus
Colymbosaurus is a colymbosaurine (derived cryptoclidid) from the Late Jurassic of the UK and Svalbard, Norway. Two valid species are known, C. megadeirus from the UK, and C. svalbardensis from Svalbard, Norway. The genus is known from the Kimmeridgian, Tithonian, and possibly early Berriasian (Late Jurassic–possibly Early Cretaceous). Benson and Bowdler (2014) revised the genus Colymbosaurus and summarised its complicated...
