Ichthyosaurus
Name means “Fish lizard”
🚫 Not a dinosaur!
Ichthyosaurus was an ichthyosaur, a dolphin-shaped reptile that spent its whole life in the sea. Dinosaurs were land animals with legs held straight under the body, and ichthyosaurs evolved on a separate branch of reptiles.
Ichthyosaurus was a sea reptile shaped like a dolphin, with huge eyes and a long, pointy snout. It was not a dinosaur!
Ichthyosaurus was a mid-sized ichthyosaur from the Early Jurassic seas of southwest England and nearby Europe. Fossils found by Mary Anning and her family helped prove that whole groups of animals had gone extinct.
Ichthyosaurus BW.jpg — Nobu Tamura (http://spinops.blogspot.com) · CC BY 3.0
Pictures
Spin it in 3D
3D model description: a 3D model of Ichthyosaurus shaped from a scientific life reconstruction painting, with the painting's colours and skin texture wrapped around it. It is not a scan of a real fossil.
About this model
This model is shaped from a scientific life reconstruction by Nobu Tamura (http://spinops.blogspot.com): the painting's outline gives the 3D body and the painting itself is its skin. It is sized to the real animal's length (about 2.4 m), so in AR it appears life-size!
It looks best from the side, like the painting it comes from. It is not a fossil scan — museums such as the Smithsonian 3D collection share real fossil scans you can explore.
What might it sound like?
Transcript: Short, whistling clicks and squeaks underwater
🤔 Nobody knows exactly how dinosaurs sounded
This is a scientific guess. We don't know if ichthyosaurs made sounds. Dolphins, which have a very similar body shape and lifestyle, use whistles and clicks, so the sound here borrows from them — but ichthyosaurs were reptiles, not mammals.
Voice boxes and soft tissue almost never fossilise, so sound reconstructions use clues: body size (bigger animals make lower sounds), the calls of living relatives (crocodiles boom with closed mouths; birds coo and hiss), and hollow structures such as hadrosaur crests that could have worked like a trumpet.
Sound: synthesised by DinoVerse from these scientific ideas (CC0). It is a creative guess, not a recording.
Food and habits
Piscivore
Fish-eater
How it ate
Chased fast prey through the water and grabbed it with a long, narrow snout full of small, sharp, cone-shaped teeth, swallowing it whole.
🔍 How do we know?
- belemnite hooks and fish scales in the stomach area
- coprolites
- small cone-shaped teeth
It ate…
- small fish
- belemnites
- squid-like cephalopods
Ichthyosaurus
…and was eaten by
- Temnodontosaurus
- large plesiosaurs
Arrows show energy moving up the food chain: from food to eater.
Watch it swim
Quick facts
| 📏 Length | 1.5–3.3 m (5–11 ft) |
|---|---|
| ↕️ Height | 0.4–0.6 m (1–2 ft) |
| ⚖️ Weight | 50–200 kg (110–440 lb) |
| ⏳ When it lived | 200–190 million years ago (Early Jurassic) |
| 📍 Fossils found | Lyme Regis, Dorset, England; Street, Somerset, England; Watchet, Somerset, England |
| 🔎 Discovered | 1811 by Joseph and Mary Anning |
| 🧬 Group | Ichthyosaurs — Diapsida › Ichthyosauromorpha › Ichthyosauria |
Where scientists disagree, we show a range. Sizes are for adults.
How big was it?
Where and when
- 📍 Lyme Regis, Dorset, England (Europe)
- 📍 Street, Somerset, England (Europe)
- 📍 Watchet, Somerset, England (Europe)
Lived 200–190 million years ago
That's about 195 million years before you were born! Humans have only existed for about 0.3 million years.
See it on the big timeline →Did you know?
- 1Ichthyosaurus looked a lot like a dolphin, but it was a reptile!
- 2It had giant eyes to help it see in dark, deep water.
- 3Ichthyosaurus mums gave birth to babies in the water — they didn't lay eggs.
- 4A girl called Mary Anning and her brother found one of the first Ichthyosaurus fossils over 200 years ago.
- Ichthyosaurs and dolphins evolved similar streamlined bodies, fins and tail flukes independently — a textbook example of convergent evolution.
- Fossil mothers with embryos inside, including some with babies emerging tail-first, show that ichthyosaurs gave birth to live young at sea, as dolphins do.
- Studies of preserved skin from related ichthyosaurs found dark melanin pigment and a fatty layer like blubber, suggesting they were warm-bodied and darkly coloured.
- In 2015 a new species, Ichthyosaurus anningae, was named in honour of Mary Anning, whose discoveries helped launch the science of palaeontology.
Myth vs fact
❌ MythIchthyosaurus was a kind of dinosaur, or a giant fish.
✅ FactIt was neither — it was an ichthyosaur, a sea reptile that breathed air, on its own branch of the reptile family tree.
❌ MythMary Anning found the very first ichthyosaur bones ever.
✅ FactOdd bones had been found before, but the Annings' specimens were the first good skulls and skeletons that helped scientists recognise ichthyosaurs as a new kind of animal.
Mini quiz
1. Is Ichthyosaurus a dinosaur?
2. What does 'Ichthyosaurus' mean?
3. Who found some of the first Ichthyosaurus fossils?
Related animals
Not a dinosaurLiopleurodon
PlesiosaurMiddle JurassicCarnivore
Not a dinosaurElasmosaurus
PlesiosaurLate CretaceousPiscivore
Not a dinosaurMosasaurus
MosasaurLate CretaceousCarnivore
Sources
Media on this page
- Ichthyosaurus BW.jpg — Nobu Tamura (http://spinops.blogspot.com) · CC BY 3.0
- Underwater light (generated background) — DinoVerse (original artwork) · CC0 1.0
- Ichthyosaurus 3D model, shaped from the life reconstruction "Ichthyosaurus BW.jpg" — Nobu Tamura (http://spinops.blogspot.com) (artwork); 3D shaping by DinoVerse · CC BY 3.0
- Ichthyosaurus reconstructed call (synthesised) — DinoVerse (synthesised) · CC0 1.0
- Ichthyosaurus communis in London.jpg — Gary Todd · CC0
- First complete ichthyosaur skeleton.jpg — Dean R. Lomax and Judy A. Massare · CC BY 4.0
- Ichthyosaurus BW.jpg — Nobu Tamura (http://spinops.blogspot.com) · CC BY 3.0
- Ichthyosaurus anningae trio NT small.jpg — Nobu Tamura email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ · CC BY-SA 4.0