AI imageNote: This dinosaur is known from only part of a skeleton. The image fills in the missing parts from close relatives, so the real animal may have looked quite different.
Match with prompt
100% (6/6 items)
See the checklist, prompt and sources
- ✓Bulky iguanodontian plant-eater on four legs, tail off the ground
- ✓Long head with a beak at the tip
- ✓Conical thumb spikes
- ✓Whole animal visible in side view
- ✓Scene matches the period and the fossil site
- ✓No text, people or modern objects
Checked by Claude Opus 5.5 (checked item by item from the image) on Oct 28, 2026. The score is the share of checklist items the image gets right; it is not an expert scientific review.
Prompt used to create the image
Scientifically accurate paleoart of Ratchasimasaurus, a herbivore Iguanodontia dinosaur from Aptian times (121.4–113.2 million years ago). A medium-sized, bulky iguanodontian plant-eater that walks on four legs, with a long tail held off the ground. Reference: Ratchasimasaurus is a genus of iguanodontian ornithopod dinosaur from Early Cretaceous Khok Kruat Formation of Nakhon Ratchasima province in northeastern Thailand. The type and only species is R. suranareae, named after Thao Suranari, a 19th-century war heroine. It was considered by one study to be a nomen dubium, diagnosed with characters widespread in Styracosterna. Anatomy: a long head with a toothless beak at the front; a conical spike on each thumb. Full body in side view, whole animal visible, standing in an Early Cretaceous floodplain like the Khok Kruat Formation of northeastern Thailand, warm and semi-arid with conifers, cycads, ferns and rare early flowering plants, no grass. Natural history museum illustration style, realistic textures and natural daylight, muted natural colors. No text, no labels, no humans, no modern objects.
Facts in the prompt come from Wikipedia (en) and Paleobiology Database
Ratchasimasaurus
Find it in a game
In Cretaceous Survival, Khok Kruat Formation · opens the game at play.dinocodex.com
Play as Ratchasimasaurus
There is no write-up for this dinosaur yet, but the scientific data below is complete.
Who lived alongside it
Dinosaurs found in the same rock formation as Ratchasimasaurus (Khok Kruat), so they lived in the same region at roughly the same time.

Nagatitan

Siamodon

Siamraptor

Sirindhorna

Psittacosaurus
Formation data from the Paleobiology Database, counting only each genus's main formations. One formation can span hundreds of thousands to millions of years, so this doesn't mean any two of them ever met.
Scientific details
- Classification
- Ornithischian (bird-hipped)
- Family
- Unknown
- When it lived
- 113.2–121.4 million years ago
- Geologic stages
- Aptian
- Named by
- Shibata et al., 2011
- Fossil occurrences
- 1 sites
🦴 Known fossil material
Parts found as fossils
- Lower jaw
Known only from a complete left lower-jaw bone (dentary), with no teeth in it. One study considered it too incomplete to be told apart from its relatives.
Note: this genus, or which bones belong to it, is still debated.
Coloured areas are parts of the skeleton with fossil bones found so far (sometimes just one bone in that area); faint areas have not been found. The outline is a general shape for its group, not this dinosaur's real body.
Compiled from published descriptions; not yet checked against the original papers by a specialist. Sources: Wikipedia (en): Ratchasimasaurus
Countries with fossils
- Thailand
Data from Paleobiology Database and Wikidata