Plesiosaurs
Look at its long neck and four flippers. All four could work together like wings under the water.
Preparing the Plesiosaurs exhibit.

Look at its long neck and four flippers. All four could work together like wings under the water.

Preparing the Plesiosaurs exhibit.
Explore together
Explore together
This is a plesiosaur. Plesiosaurs were sea reptiles that lived alongside dinosaurs, but they were not dinosaurs. Look at its long neck and four flippers. All four could work together like wings under the water.
Classification used here: Marine reptiles. Fossils assigned to Plesiosaurs are known from Late Triassic to Late Cretaceous and have been found in Ancient marine rocks around the world. The museum uses 1.5–13 m (about 5–43 ft) as the reference group size range and describes the diet as meat-eater. Plesiosaurs varied greatly in size; this is not the length of the animal shown. Plesiosaurs were a large group of extinct marine reptiles, not dinosaurs. Some had a long neck and small head, while others had a shorter neck and larger head. Their unusual four-flipper arrangement may have allowed all four limbs to help provide steady thrust. The model source gives no genus, species or specimen, so this label stays at group level.
Leon Made This compiled these research notes from public museum resources and scientific papers while preserving uncertainty in the reconstruction. Last reviewed 2026-08-07.
The code is licensed under AGPL-3.0. Original science writing and project artwork use CC BY-NC-SA 4.0 for non-commercial sharing. The brand policy prevents impersonation, and third-party assets keep their original licences.
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Prehistoric Animal Museum is made and maintained by Leon Made This. Use these addresses to verify the official project and its creator.
More information is available below.
Leon Made This
I’m Leon, a developer and a dad. When my daughter was three, dinosaur chases on television frightened her, so I made a 3D prehistoric animal museum where she could look quietly and listen only when she wanted to.
The museum is free, with no sign-up, adverts or visitor tracking. Finding one interesting detail at a time is plenty.
Official source
Prehistoric Animal Museum is made and maintained by Leon Made This. Use these addresses to verify the official project and its creator.