Plesiosaurus fossil map
Where fossils of Plesiosaurus have been found, shown on the Earth as it looked about 175 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 175 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Plesiosaurs & kin |
|---|---|
| Lived | 205.7–66 million years ago (Rhaetian to Maastrichtian) |
| Periods | Triassic, Jurassic, Cretaceous |
| Named by | de la Beche and Conybeare 1821 |
| Fossil records | 55 occurrences at 43 locations (PBDB) |
| Found in | UK, France, United States, Belgium, New Zealand, South Africa, Mexico, Japan, Chile, Australia … |
| Rock formations | txn:NF, Kimmeridge Clay, Charmouth Mudstone, Westbury, Grès de Mortinsart, Argiles de Châtillon |
About Plesiosaurus
Plesiosaurus (Greek: πλησίος (plesios), near to + σαῦρος (sauros), lizard) is a genus of extinct, large marine sauropterygian reptile that lived during the Early Jurassic. It is known by nearly complete skeletons from the Lias of England. Measuring around 3.5 m (11 ft) long, it is distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles. It lends its name to the order Plesiosauria, of which it is an early, but fairly typical member. It contains only one species, the type, Plesiosaurus dolichodeirus. Other species once assigned to this genus, including P. brachypterygius, P. guilielmiimperatoris, and P. tournemirensis have been reassigned to new genera, such as Hydrorion, Seeleyosaurus and Microcleidus.
Text in “About” is quoted from the Wikipedia article Plesiosaurus (revision 1374370901), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 22 October 2026. Ages are those of the rock layers the fossils were found in.
