Temporal range: Late Triassic - Late Cretaceous, 203–66.0 Ma[1]
PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Restored skeleton of Plesiosaurus
Skeletal mount of Peloneustes
Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Phylum:
Chordata
Class:
Reptilia
Superorder:
†Sauropterygia
Clade:
†Pistosauria
Order:
†Plesiosauria Blainville, 1835
Subgroups
†Anningasaura
†Lindwurmia
†Zahrisaurus
†Termatosaurus?
†Alexeyisaurus?
†Neoplesiosauria
†Plesiosauroidea
†Pliosauroidea
The Plesiosauria (/ˌpliːsiəˈsɔːriə,-zi-/PLEE-see-ə-SOR-ee-ə, -zee-;[2][3] Greek: πλησίος, plesios, meaning "near to" and sauros, meaning "lizard")[4] or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia.
Plesiosaurs first appeared in the latest Triassic Period, possibly in the Rhaetian stage, about 203 million years ago.[5] They became especially common during the Jurassic Period, thriving until their disappearance due to the Cretaceous–Paleogene extinction event at the end of the Cretaceous Period, about 66 million years ago. They had a worldwide oceanic distribution, and some species at least partly inhabited freshwater environments.[6]
Plesiosaurs were among the first fossil reptiles discovered. In the beginning of the nineteenth century, scientists realised how distinctive their build was and they were named as a separate order in 1835. The first plesiosaurian genus, the eponymous Plesiosaurus, was named in 1821. Since then, more than a hundred valid species have been described. In the early twenty-first century, the number of discoveries has increased, leading to an improved understanding of their anatomy, relationships and way of life.
Plesiosaurs had a broad flat body and a short tail. Their limbs had evolved into four long flippers, which were powered by strong muscles attached to wide bony plates formed by the shoulder girdle and the pelvis. The flippers made a flying movement through the water. Plesiosaurs breathed air, and bore live young; there are indications that they were warm-blooded.
Plesiosaurs showed two main morphological types. Some species, with the "plesiosauromorph" build, had (sometimes extremely) long necks and small heads; these were relatively slow and caught small sea animals. Other species, some of them reaching a length of up to seventeen metres, had the "pliosauromorph" build with a short neck and a large head; these were apex predators, fast hunters of large prey. The two types are related to the traditional strict division of the Plesiosauria into two suborders, the long-necked Plesiosauroidea and the short-neck Pliosauroidea. Modern research, however, indicates that several "long-necked" groups might have had some short-necked members or vice versa. Therefore, the purely descriptive terms "plesiosauromorph" and "pliosauromorph" have been introduced, which do not imply a direct relationship. "Plesiosauroidea" and "Pliosauroidea" today have a more limited meaning. The term "plesiosaur" is properly used to refer to the Plesiosauria as a whole, but informally it is sometimes meant to indicate only the long-necked forms, the old Plesiosauroidea.
^Colbert, Edwin H. (Edwin Harris); Knight, Charles Robert (1951). The dinosaur book: the ruling reptiles and their relatives. New York: McGraw-Hill. p. 153.
^"The Plesiosaur Directory". Archived from the original on 4 March 2016. Retrieved 20 April 2013.
^"Plesiosaur fossils found in the Sahara suggest they weren't just marine animals". ScienceDaily. 27 July 2022. Archived from the original on 29 July 2022. Retrieved 3 August 2022.
meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in...
This list of plesiosaurs is a comprehensive listing of all genera that have ever been included in the order Plesiosauria, excluding purely vernacular...
belong to the latter. Gastroliths are frequently found associated with plesiosaurs. The first complete plesiosauroid skeletons were found in England by...
Elasmosauridae is an extinct family of plesiosaurs, often called elasmosaurs. They had the longest necks of the plesiosaurs and existed from the Hauterivian...
is no plesiosaur", Leslie Noè of the Sedgwick Museum in Cambridge said: "The osteology of the neck makes it absolutely certain that the plesiosaur could...
correctly identified ichthyosaur skeleton, the first two nearly complete plesiosaur skeletons, and the first pterosaur skeleton outside Germany. Her observations...
Leptocleidus is an extinct genus of plesiosaur, belonging to the family Leptocleididae. It was a small plesiosaur, measuring only up to 3 m (9.8 ft)....
This timeline of plesiosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, taxonomic revisions...
Pliosauroidea is an extinct clade of plesiosaurs, known from the earliest Jurassic to early Late Cretaceous. They are best known for the subclade Thalassophonea...
the presence of gastroliths in elasmosaurid plesiosaurs differs from that of the short-necked plesiosaurs. While some fossil gastroliths are rounded and...
Conybeare in 1824 on the basis of Anning's original finds. Compared to other plesiosaur genera, Plesiosaurus has a small head. The skull is much narrower than...
surviving specimens of giant marine reptiles, such as an ichthyosaur or plesiosaur, from the Jurassic and Cretaceous Periods, or extinct whales like Basilosaurus...
Rarosaurus is an extinct genus of polycotylid plesiosaur that lived during the Late Cretaceous. It contains one valid species, R. singularis and it was...
tons), but P. rossicus and P. funkei would have been one of the largest plesiosaurs of all time, exceeding 10 metres (33 ft) in length. This genus has contained...
Elasmosaurus (/ɪˌlæzməˈsɔːrəs, -moʊ-/) is a genus of plesiosaur that lived in North America during the Campanian stage of the Late Cretaceous period, about...
of plesiosaur crossed the Triassic–Jurassic boundary. Plesiosaurs were already diverse in the earliest Jurassic, with the majority of plesiosaurs in the...
krip-toh-KLY-dəs) is a genus of plesiosaur reptile from the Middle Jurassic period of England, France, and Cuba. Cryptoclidus was a plesiosaur whose specimens include...
except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic. Sauropterygians...
Moanasaurus, was one of the largest mosasaurs in the world. The New Zealand plesiosaur is named Mauisaurus. Fauna of New Zealand List of geckos of New Zealand...
Styxosaurus is a genus of plesiosaur of the family Elasmosauridae. Styxosaurus lived during the Campanian age of the Cretaceous period. Three species are...
Nichollssaura is an extinct genus of leptocleidid plesiosaur from the Early Cretaceous Boreal Sea of North America. The type species is N. borealis, found...
Attenborough and his works Timeline of plesiosaur research List of plesiosaur genera Bakker, R. T. (1993). Plesiosaur extinction cycles - events that mark...
2011. List of plesiosaur genera Timeline of plesiosaur research Storrs, G. W & Taylor, M. A. (1996). Cranial anatomy of a new plesiosaur genus from the...
the year 1812. Refer to article on these carnivorous aquatic reptiles. Plesiosaurs (sensu Plesiosauroidea) appeared at the start of the Jurassic Period...
belonging to the Thalassophonea, a clade of short-necked pliosaurid plesiosaurs. Liopleurodon lived from the Callovian Stage of the Middle Jurassic to...
Dolichorhynchops is an extinct genus of polycotylid plesiosaur from the Late Cretaceous of North America, containing the species D. osborni and D. herschelensis...
Futabasaurus is a genus of plesiosaur from the Late Cretaceous of Fukushima, Japan. It was described and named in 2006, and was assigned to the family...
mosasaurs such as Prognathodon overtoni and Plioplatecarpus peckensis, plesiosaurs such as Dolichorhynchops herschelensis, Albertonectes and Nakonanectes...
Global Information
