Welcome to plesiosauria.com! The Plesiosaur Directory is your online resource for everything 'plesiosaur'. During the Mesozoic Era between 245 to 65 million years ago when dinosaurs dominated the land, the waters of the world were inhabited by an equally spectacular variety of reptiles. Amongst the first fossil vertebrates to be discovered and recognised by scientists, these 'sea-dragons' occurred in all sorts of shapes and sizes. But perhaps the most unusual group of fascinating extinct prehistoric marine reptiles is the sauropterygians: plesiosaurs and their kin.

Sauropterygians are a group of carnivorous diapsid reptiles. The most popular and widely recognised of these are the long-necked plesiosauroids, they have four large flippers, short tails and barrel shaped bodies. The closely related pliosauroids (often just called 'pliosaurs') have shorter necks and large heads. However, sauropterygians were very diverse and there are many other interesting forms including the placodonts, pachypleurosaurs, nothosaurs, and an array of intermediates.

This website is designed to be a resource for anyone interested in any aspect of the plesiosaurs and their kin. This is a long-term aim and the site will always be under development, as our understanding of plesiosaurs develops. You will find scientific information regarding the anatomy, classification and evolution of the group, information on specific genera and species, and data on their palaeobiology; how the animals were in life, how they swam and what ate. Keep up to date with the latest discoveries on the News page. I also include pages about the people behind the science (in development), and about plesiosaurs in popular culture: films, toys and monsters. I have endeavoured to make this site as image-rich as possible, using photographs of fossils, reconstructions of fossils, and restorations of the possible appearance of the animals in life. Plus, you can get your fill of plesiosaur books and toys in the Plesio-Store, and join in the ongoing discussions at the Marine Reptile Forum.

I hope you enjoy your stay!

Dr Adam Stuart Smith