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% (5/5 items)
See the checklist, prompt and sources
- ✓Early relative of duck-billed dinosaurs, broad beak, no crest
- ✓About 6 m long, walks on four or two legs, tail held straight out
- ✓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 Sirindhorna, a herbivore Hadrosauroidea dinosaur from Aptian times (121.4–113.2 million years ago). An early relative of duck-billed dinosaurs with a broad beak and NO head crest. Reference: Sirindhorna is a genus of hadrosauroid ornithopod dinosaur from Early Cretaceous deposits of northeastern Thailand. Anatomy: about 6 meters long, walks on four legs or two, tail held straight out. 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
Sirindhorna
Name meaning: Named in honor of Her Royal Highness Princess Maha Chakri Sirindhorn.
📏 About 6 m long, roughly two pickup trucks end to end.
📐 Compare its size with other dinosaurs →Find it in a game
In Cretaceous Survival, Khok Kruat Formation · opens the game at play.dinocodex.com
Play as Sirindhorna
Sirindhorna was a plant-eater and an early relative of the duck-billed dinosaurs (hadrosaurs), found in the Khok Kruat Formation of Nakhon Ratchasima province. It is one of the Thai dinosaurs named with royal permission after the Princess.
Fun facts
- Sirindhorna helps scientists understand how duck-billed dinosaurs arose and evolved in Asia in the Early Cretaceous.
- Its fossils include several skull bones that show the shape of its head and teeth fairly clearly.
Who lived alongside it
Dinosaurs found in the same rock formation as Sirindhorna (Khok Kruat), so they lived in the same region at roughly the same time.
Nagatitan
Ratchasimasaurus
Siamodon
Siamraptor
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., 2015
- Fossil occurrences
- 1 sites
🦴 Known fossil material
Parts found as fossils
- Skull
- Lower jaw
- Teeth
Holotype: a braincase. Skull bones, upper and lower jaws and teeth from the same site have been referred to it.
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): Sirindhorna
Countries with fossils
- Thailand
Data from Paleobiology Database and Wikidata