Prehistoric Animal Museum

Meet today’s friendAn ancient relative of mammals

Dimetrodon

A tall sail along the back and a long tail behind.

Dimetrodon’s tall sail rose above its back like a little hill. It lived before dinosaurs and was a distant relative of today’s mammals.

Still model of Dimetrodon on a transparent background

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Preparing the Dimetrodon exhibit.

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Guide for grown-ups

When it lived: Early Permian
Where fossils were found: North America and Europe
Body length: 3 m (about 10 ft)
Diet: Meat-eater
What kind of animal?: An ancient relative of mammals. Dimetrodon lived before dinosaurs and was related to today’s mammals. Its tall back sail makes it easy to recognise.

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Narration transcript

Dimetrodon’s tall sail rose above its back like a little hill. It lived before dinosaurs and was a distant relative of today’s mammals.

Research notes about Dimetrodon

Research summary

Fossils of Dimetrodon date to the Early Permian and have been found in North America and Europe.

Learning from fossils

Different species varied in size. Scientists are still studying what the sail was used for.

Scientific sources

Dimetrodon growth research at Museum für Naturkunde BerlinAccessed 2026-10-22

Leon Made This compiled these research notes from public museum resources and scientific papers while preserving uncertainty in the reconstruction. Last reviewed 2026-10-22.

3D model and asset credits

异齿龙: “异齿龙” by cp4096, CC BY 4.0; modified for the Prehistoric Animal Museum. Creative Commons Attribution 4.0 International

Open source and licensing

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.

View the GitHub project Read the full licensing notes

Official source

Made by Leon Made This

Prehistoric Animal Museum is made and maintained by Leon Made This. Use these addresses to verify the official project and its creator.

Official Prehistoric Animal Museumhttps://leon-made-this.work/museum/en/Leon's personal websitehttps://leon-made-this.work/

More information is available below.

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Leon Made This

About this museum

A little museum made by a developer dad for his daughter

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

Made by Leon Made This

Prehistoric Animal Museum is made and maintained by Leon Made This. Use these addresses to verify the official project and its creator.

Official Prehistoric Animal Museumhttps://leon-made-this.work/museum/en/Leon's personal websitehttps://leon-made-this.work/

View the source on GitHub Read the licence and asset notes