Pliosauridae

Liopleurodon (; meaning 'smooth-sided teeth') is an extinct genus of carnivorous pliosaurid plesiosaurs that lived from the Callovian stage of the Middle Jurassic to the Kimmeridgian stage of the Late Jurassic period (approximately 166 to 155 million years ago). The type species is L. ferox, which is probably the only valid species. Some studies also include the second species L. pachydeirus, but this latter is considered as a probable junior synonym of L. ferox due to its lack of viable diagnosis. Fossils attributed to Liopleurodon, including some skeletons, are mainly known from Europe, with

Kronosaurus ( ) is an extinct genus of large short-necked pliosaur that lived during the Aptian to Albian stages of the Early Cretaceous in what is now Australia. The first known specimen was received in 1899 and consists of a partially preserved mandibular symphysis, which was first thought to come from an ichthyosaur according to Charles De Vis. However, it was in 1924 that Albert Heber Longman formally described this specimen as the holotype of an imposing pliosaurid, to which he gave the scientific name K. queenslandicus, which is still the only recognized species nowadays. The genus name,

Pliosaurus is the type genus (defining example) of the pliosaurs, one of the major group of the plesiosaurs, an extinct group of aquatic marine reptiles. It lived from the Upper Jurassic to the Lower Cretaceous in what is now Europe and South America. The first known fossil consists of a partial skeleton of an immature specimen collected by William Buckland in Market Rasen, England. Although initially mentioned in a 1824 paper by William Daniel Conybeare, it was not until 1841 that it was first formally described by Richard Owen as belonging to a new species of Plesiosaurus, before being given

Peloneustes (meaning ) is a genus of pliosaurid plesiosaur from the Middle Jurassic of England. Its remains are known from the Peterborough Member of the Oxford Clay Formation, which is Callovian in age. It was originally described as a species of Plesiosaurus by palaeontologist Harry Govier Seeley in 1869, before being given its own genus by naturalist Richard Lydekker in 1889. While many species have been assigned to this genus, P. philarchus is currently the only one still considered valid, with the others moved to different genera, considered nomina dubia, or synonymised with P. philarchus

Attenborosaurus is an extinct genus of pliosaurid from the Early Jurassic of Dorset, England. The type species is A. conybeari. The genus is named after Sir David Attenborough, the species after William Conybeare.

Brachauchenius (meaning 'short neck') is an extinct genus of pliosaurs that lived during the Late Cretaceous in what are now North America and North Africa. Only one species is known, B. lucasi, initially described by Samuel Wendell Williston in 1903 from a partial fossil skeleton discovered in a quarry in Kansas, United States. Many other fossil specimens attributed to the species were subsequently discovered, including an individual from Morocco whose presence was made official in 2016. Many contemporary pliosaur specimens were formerly attributed to Brachauchenius, but have since been reide

Simolestes (meaning "snub-nosed thief") is an extinct pliosaurid genus that lived in the Middle to Late Jurassic. The type specimen, NHMUK PV R 3319 is an almost complete but crushed skeleton diagnostic to Simolestes vorax, dating back to the Callovian of the Oxford Clay formation, England. The genus might also be known from the Tithonian Bhuj Formation of India (S. indicus), but the referral of this species to Simolestes is dubious. S. keileni from France was moved to the new genus Lorrainosaurus in 2023.

Pliosauridae is a family of plesiosaurian marine reptiles from the Latest Triassic to the early Late Cretaceous (Rhaetian to Turonian stages). The family is more inclusive than the archetypal short-necked large headed species that are placed in the subclade Thalassophonea, with early, primitive forms resembling other plesiosaurs with long necks.

Thalassiodracon (tha-LAS-ee-o-DRAY-kon) is an extinct genus of plesiosauroid from the Pliosauridae that was alive during the Late Triassic-Early Jurassic (Rhaetian-Hettangian) and is known exclusively from the Lower Lias of England. The type and only species, is Thalassiodracon (Plesiosaurus) hawkinsii (Owen, 1838).

Polyptychodon (meaning 'many-folded tooth') is a genus of pliosaurid found in Middle-Late Cretaceous marine deposits in southern England, France and Argentina. It has been considered a nomen dubium in a 2016 review.

Megacephalosaurus (; "great-headed lizard") is an extinct genus of short-necked pliosaur that inhabited the Western Interior Seaway of North America about 94 to 93 million years ago during the Turonian stage of the Late Cretaceous, containing the single species M. eulerti. It is named after its large head, which is the largest of any plesiosaur in the continent and measures up to in length. Megacephalosaurus was one of the largest marine reptiles of its time with an estimated length of . Its long snout and consistently sized teeth suggest that it preferred a diet of smaller-sized prey.

Sinopliosaurus (meaning "Chinese more lizard") is a dubious genus of pliosauroid plesiosaur. It lived during the Aptian and Albian stages of the Early Cretaceous (disputed Sinopliosaurus remains have been dated to the Toarcian age and were found in the Ziliujing Formation) of the People's Republic of China - its exact age is unknown. The type species, Sinopliosaurus weiyuanensis, was named and described in 1944 by Yang Zhongjian. One species, "S." fusuiensis, was later shown to be based on teeth from a spinosaurid theropod dinosaur which is now known as Siamosaurus. S. weiyuanensis was conside

Gallardosaurus is a genus of pliosaurid plesiosaur from the Caribbean seaway. It contains the single species Gallardosaurus iturraldei. Gallardosaurus was found in middle-late Oxfordian-age (Late Jurassic) rocks of the Jagua Formation of western Cuba. Gallardosaurus is believed to be evolutionarily connected to Peloneustes, a pliosaurid commonly found in the Oxfordian-aged sediment.

Hauffiosaurus is an extinct genus of Early Jurassic (early Toarcian stage) pliosaurid plesiosaur known from Holzmaden of Germany and from Yorkshire of the United Kingdom. It was first named by Frank Robin O’Keefe in 2001 and the type species is Hauffiosaurus zanoni. In 2011, two additional species were assigned to this genus: H. longirostris and H. tomistomimus.

Marmornectes is a genus of pliosaurid known from the Middle Jurassic of Bedfordshire, United Kingdom.

Sachicasaurus is an extinct genus of brachauchenine pliosaurid known from the Barremian of the Paja Formation, Altiplano Cundiboyacense in the Colombian Eastern Ranges of the Andes. The type species is S. vitae.

Stenorhynchosaurus is an extinct genus of pliosaurid plesiosaurs which lived in the Early Cretaceous of South America. The type species and only known is Stenorhynchosaurus munozi.

Pachycostasaurus (meaning 'thick-ribbed lizard') is an extinct Pliosauroid from the Oxford Clay formation of Peterborough, England.

Acostasaurus (meaning "Acosta's lizard") is an extinct genus of possibly Thalassophonean pliosaurid known from the Barremian of the Paja Formation, Colombia. The type specimen, UNDG R-1000, is known from a near complete skull, and postcranial elements including a complete hindlimb and various vertebrae. The specimen has an estimated size of over in length.

Lorrainosaurus is an extinct genus of thalassophonean pliosaurid from the Middle Jurassic of Lorraine, France.

Monquirasaurus ("Monquirá lizard") is an extinct genus of giant short-necked pliosaurs who lived during the Early Cretaceous (Aptian) in what is now Colombia. One species is known, M. boyacensis, described in 2021 from an almost complete fossil skeleton, discovered in 1977 in the town of Villa de Leyva, located in Boyacá. Published descriptions of the holotype specimen estimate that it should reach a total size approaching in length and weighing , making Monquirasaurus a large representative of the pliosaurids.

Luskhan (meaning "water spirit chief") is an extinct genus of large pliosaurid plesiosaurs from the Lower Cretaceous of western Russia. The only known species is L. itilensis, first described in 2017 from a well-preserved and nearly complete skeleton discovered in the Ulyanovsk region. As an early-diverging brachauchenine, Luskhan consequently exhibits an intermediate combination of traits seen in more basal (less specialized) and more derived (more specialized) pliosaurs. However, Luskhan departs significantly from other pliosaurs in that it exhibits a lack of adaptations in its skull to feed

Anguanax is an extinct genus of basal pliosaurid known from the Late Jurassic (Oxfordian stage) Rosso Ammonitico Veronese Formation of northern Italy. It contains a single species, Anguanax zignoi, known from a partially complete individual, representing the first articulated skeleton of an Italian plesiosaurian.

Arminisaurus (meaning "lizard of Arminius") is a genus of pliosaurid plesiosaur that lived during the Lower Jurassic in present-day Germany. With Westphaliasaurus and Cryonectes, Arminisaurus is only the third plesiosaurian taxon that was described from the Pliensbachian stage. The holotype and only known specimen is a fragmentary skeleton (about 40 percent complete), comprising an incomplete lower jaw, teeth, vertebrae and elements from the pectoral girdle and the paddles. The animal had an estimated body length of .

species of reptile (fossil)

Eardasaurus is a genus of thalassophonean pliosaurid from the middle Jurassic Oxford Clay Formation. The animal would have measured over long (the tail was not fully preserved) and possessed a high amount of teeth relative to other pliosaurs. Its teeth show distinct ridges formed by the tooth enamel, some of which are very pronounced and similar to carinae, giving the teeth a cutting edge.

Eiectus is a potentially valid genus of extinct short-necked pliosaur that lived in the Early Cretaceous period. Fossil material has been recovered from the Wallumbilla Formation (Aptian) of Queensland was initially classified under the related genus Kronosaurus until 2021.