The type species Woolungasaurus glendowerensis, named by Per Ove Persson in 1960, is known from a partial skeleton, holotype QM F6890, (forty-six vertebrae, ribs, forearms, shoulder girdle and part of the rear limbs) unearthed from the Wallumbilla Formation (Albian, Lower Cretaceous) of the Richmond District, Queensland, Australia. The specific name refers to Glendower Station. Another find of undetermined species, consisting of twelve vertebrae, was unearthed from the Maree Formation (Cretaceous, of uncertain age) of Neales River, near Lake Eyre, South Australia. In addition a skull from Yamborra Creek, near Maxwelltown, Queensland, described by Persson in 1982 has been referred to Woolungasaurus.
Woolungasaurus appears to have been a typical elasmosaur, with forty sharp teeth and an estimated length of about 9.5 metres. Persson (1982) believes it to be closely related to the North American elasmosaur Hydralmosaurus.
Temporal range: Early Cretaceous
P.O. Persson 1960
Aristonectinae is a clade of plesiosaurs in the family Elasmosauridae. It includes the Late Cretaceous plesiosaurs Aristonectes and Kaiwhekea, traditionally grouped with the Late Jurassic Tatenectes and Kimmerosaurus in the family Aristonectidae. In recent years, multiple specimens were collected in Angola.Cryptoclidia
Cryptoclidia is a clade of plesiosaurs.
Cryptoclidia was named and defined as a node clade in 2010 by Hilary Ketchum and Roger Benson: the group consisting of the last common ancestor of Cryptoclidus eurymerus and Polycotylus latipinnis; and all its descendants.The following cladogram follows an analysis by Benson & Druckenmiller (2014).Fresnosaurus
Fresnosaurus is an extinct genus of plesiosaur from the Late Cretaceous (Maastrichtian stage) of what is now California. The type species is Fresnosaurus drescheri, first described by Welles in 1943. The generic name Fresnosaurus honors Fresno County, while the specific name honors Arthur Drescher.
Fresnosaurus was probably at least 30 feet in length. Like all elasmosaurid plesiosaurs, it probably ate small bony fish, belemnites, and ammonites.Hydrorion
Hydrorion (meaning 'water hunter') is an extinct genus of plesiosaur. It was found in Jurassic formations in Germany to Posidonia Shale formation.Leptocleididae
Leptocleididae is a family of small-sized plesiosaurs that lived during the Early Cretaceous period (early Berriasian to early Albian stage). Leptocleidus and Umoonasaurus had round bodies and triangle-shaped heads. Hilary F. Ketchum and Roger B. J. Benson (2010), transferred Brancasaurus, Kaiwhekea, Nichollssaura and Thililua to this family. However, Ketchum and Benson (2011) reassigned Kaiwhekea and Thililua to their original positions, as an elasmosaurid and a polycotylid, respectively.Manemergus
Manemergus is a genus of polycotylid plesiosaur from the Late Cretaceous (Turonian) of Morocco. Manemergus was described in 2005 and contains only one species, M. anguirostris. The type specimen was discovered close to the town of Goulmima (Tizi-n-Imnayen) in Morocco's High Atlas mountains, in the same locality as another polycotylid, Thililua, was discovered.Maresaurus
Maresaurus is an extinct genus of pliosaur from the Middle Jurassic (Bajocian) of what is now Argentina. The type species, Maresaurus coccai, was named by Gasparini in 1997. Recent phylogenetic analysis found Maresaurus to be a rhomaleosaurid.Meyerasaurus
Meyerasaurus is an extinct genus of rhomaleosaurid known from Holzmaden, Baden-Württemberg of southwestern Germany.Orophosaurus
Orophosaurus is an extinct genus of plesiosaur.Picrocleidus
Picrocleidus is an extinct genus of plesiosaur. It is known only from the type species P. beloclis from the Middle Jurassic Oxford Clay Formation (Callovian stage) of the United Kingdom.Plesiopterys
Plesiopterys is an extinct genus of plesiosaur.Plesiosauridae
The Plesiosauridae are a monophyletic group of plesiosaurs.A family Plesiosauridae was first named by John Edward Gray in 1825.Pliosauridae
Pliosauridae is a family of plesiosaurian marine reptiles from the Earliest Jurassic to the early Late Cretaceous (Hettangian to Turonian stages) of Australia, Europe, North America and South America. Past the Turonian, they may have been replaced by the mosasaurs. It was formally named by Harry G. Seeley in 1874.Seeleyosaurus
Seeleyosaurus is an extinct genus of plesiosaur. It is known from a large almost complete skeleton from the Upper Lias (Toarcian) of Württemberg, Germany. There seems to be the impression of a rhomboidal flap of skin in a vertical plane; if so, many plesiosaurs may have been equipped in this way.Spitrasaurus
Spitrasaurus is an extinct genus of cryptoclidid plesiosauroid plesiosaur known from the uppermost Jurassic of central Spitsbergen, Norway. It is named after a portmanteau of Spitsbergen Travel.Sulcusuchus
Sulcusuchus is a genus of polycotylid plesiosaur from the Late Campanian of Argentina.Thalassomedon
Thalassomedon (from Greek, thalassa, "sea" and Greek, medon, "lord" or "ruler", meaning "sea lord") is a genus of plesiosaur, named by Welles in 1943.Trinacromerum
Trinacromerum is an extinct genus of sauropterygian reptile, a member of the polycotylid plesiosaurs. It contains two species, T. bentonianum and T. kirki. Specimens have been discovered in the Late Cretaceous fossil deposits of what is now modern Kansas and Manitoba.Zarafasaura
Zarafasaura is an extinct genus of elasmosaurid known from the Oulad Abdoun Basin of Morocco.