Plesiosaurs were long-necked marine reptiles, closely related to the Pliosaurs though probably slower in the water. Their swimming speed has been estimated at 8.2km/h, which is faster than an Olympic champion, but too slow to catch a mackerel, salmon or seal. Plesiosaurs are often depicted with their neck bent into sinuous folds. In truth it was not that flexible, and no Plesiosaur ever bent its neck into the tight curve today's swans can manage. Plesiosaurs became extinct at the same time as the dinosaurs.
Scientific name: Plesiosauroidea
near, close to lizard
The following habitats are found across the Plesiosaurs distribution range. Find out more about these environments, what it takes to live there and what else inhabits them.
Discover what these behaviours are and how different plants and animals use them.
Additional data source: Animal Diversity Web
Discover the other animals and plants that lived during the following geological time periods.
Plesiosauria (/ˌpliːsi.ɵˈsɔriə/; Greek: plesios meaning 'near to' and sauros meaning 'lizard') is an order of Mesozoic marine reptiles (sauropsida). Plesiosaurs first appeared in the Early Jurassic (and possibly Rhaetian, latest Triassic) Period and became especially common during the Jurassic Period, thriving until the Cretaceous–Paleogene extinction at the end of the Cretaceous Period. They had a worldwide distribution.
The name "plesiosaur" is used to refer to the order Plesiosauria as a whole, not only to the long-necked forms (suborder Plesiosauroidea). These latter constitute the plesiosaurs in the popular imagination ("Nessie", "Nahuelito").
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