Amargasaurus
Name means “La Amarga lizard”
Amargasaurus was a small long-necked dinosaur with two rows of tall spikes running down its neck and back. It lived in what is now Argentina.
Amargasaurus cazaui was a dicraeosaurid sauropod from the Early Cretaceous of Patagonia, notable for two parallel rows of very long neural spines on its neck. What these spines looked like in life, and what they were for, is still debated.
Amargasaurus NT small.jpg — Nobu Tamura email:nobu.tamura@yahoo.com http://spi · CC BY-SA 4.0
Pictures
Spin it in 3D
3D model description: a 3D model of Amargasaurus 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 email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ http://paleoexhibit.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 9.5 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: Low, hollow bellow, about 3 seconds long
🤔 Nobody knows exactly how dinosaurs sounded
This sound is a scientific guess. Amargasaurus was small for a sauropod, so it may have had a slightly higher voice than the giants, but like birds and crocodiles it probably made low, closed-mouth calls rather than roars.
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
Herbivore
Plant-eater
How it ate
Browsed on low to mid-height plants, holding its fairly short neck sloping downwards with the snout close to the ground, and nipping off leaves with pencil-like teeth before swallowing them whole.
🔍 How do we know?
- narrow pencil-like teeth like other dicraeosaurids
- CT scans of the inner ear and neck joints suggesting a downward-facing snout about 80 cm above the ground
- plant fossils from the La Amarga Formation
It ate…
- Ferns
- Horsetails
- Cycads
- Low conifers
Amargasaurus
…and was eaten by
👑 Probably nothing, once fully grown — a top predator or too big to tackle!
Arrows show energy moving up the food chain: from food to eater.
Watch it feed
Quick facts
| 📏 Length | 9–10 m (30–33 ft) |
|---|---|
| ↕️ Height | 2.4–3 m (8–10 ft) |
| ⚖️ Weight | 2,600–4,000 kg (5,730–8,820 lb) |
| ⏳ When it lived | 129–122 million years ago (Early Cretaceous) |
| 📍 Fossils found | La Amarga Formation, near Zapala, Neuquén, Argentina |
| 🔎 Discovered | 1984 by Expedition led by José Bonaparte (named by Leonardo Salgado and José Bonaparte, 1991) |
| 🧬 Group | Sauropods — Saurischia › Sauropodomorpha › Sauropoda |
Where scientists disagree, we show a range. Sizes are for adults.
How big was it?
Where and when
- 📍 La Amarga Formation, near Zapala, Neuquén, Argentina (South America)
Lived 129–122 million years ago
That's about 126 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?
- 1Amargasaurus had two rows of spikes on its neck, some longer than your arm!
- 2Compared with other long-necked dinosaurs, it was quite small, about as long as a bus.
- 3Its name comes from La Amarga, the canyon in Argentina where it was found.
- 4It probably ate low plants, like ferns, close to the ground.
- The longest neck spines reached about 60 cm and were paired, leaving only a few centimetres between the two rows, which makes the old idea of two separate skin sails unlikely.
- Hypotheses for the spines include display to rivals or mates, defence, or a single skin sail; a 2022 bone-structure study by Cerda and colleagues argued against the popular idea of a long horny sheath on each spine.
- It belongs to Dicraeosauridae, a family of relatively short-necked sauropods related to Diplodocus that likely fed low to the ground.
- It is known from a single, fairly complete skeleton found in 1984, so details like its body size are estimated from that one individual.
Myth vs fact
❌ MythAmargasaurus definitely had two big skin sails on its neck.
✅ FactThe two rows of spines were very close together, so two separate sails are unlikely. Scientists still debate whether it had one sail, bare spikes or something in between.
Mini quiz
1. What was special about Amargasaurus's neck?
2. In which country was Amargasaurus found?
3. When did Amargasaurus live?
Related animals
Diplodocus
SauropodLate JurassicHerbivore
Argentinosaurus
SauropodLate CretaceousHerbivore
Saltasaurus
SauropodLate CretaceousHerbivore
Sources
Media on this page
- Amargasaurus NT small.jpg — Nobu Tamura email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ http://paleoexhibit.b · CC BY-SA 4.0
- Fern in forest by I. Levitan (1895, N. Novgorod).jpg — Isaac Levitan · Public domain
- Amargasaurus 3D model, shaped from the life reconstruction "Amargasaurus NT small.jpg" — Nobu Tamura email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ http://paleoexhibit.b · CC BY-SA 4.0
- Amargasaurus reconstructed call (synthesised) — DinoVerse (synthesised) · CC0 1.0
- Amargasaurus in Prague National Museum.jpg — Jan Helebrant · CC0
- Amargasaurus, MEF Trelew 02.JPG — Gastón Cuello · CC BY-SA 4.0
- Amargasaurus NT small.jpg — Nobu Tamura email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ http://paleoexhibit.b · CC BY-SA 4.0
- Amargasaurus Reconstruction Fred Wierum.png — Fred Wierum · CC BY-SA 4.0