Siamodon Facts
| Diet | Herbivore |
| Height | 2m |
| Length | 5m |
| Weight | 1 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Early Cretaceous |
| Type | Ornithopod |
| Location | Thailand |

| Diet | Herbivore |
| Height | 2m |
| Length | 5m |
| Weight | 1 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Early Cretaceous |
| Type | Ornithopod |
| Location | Thailand |
Siamodon was a plant-eating ornithopod dinosaur that lived in what is now northeastern Thailand during the Early Cretaceous period, approximately 121 million years ago. This medium-sized herbivore represents one of the earliest known hadrosauroid dinosaurs from Southeast Asia, providing important insights into the evolution and distribution of duck-billed dinosaur relatives in this region.
Standing about 2 metres tall at the hip and measuring roughly 5 metres in length, Siamodon was built for efficient plant processing. Like other ornithopods, it possessed specialised teeth designed for grinding tough vegetation, with multiple rows of replacement teeth that continuously grew throughout its lifetime. Its jaw structure suggests it was capable of sophisticated chewing motions that helped break down fibrous plant material.
Siamodon likely spent much of its time browsing on ferns, cycads, and early flowering plants that grew in the warm, humid climate of Cretaceous Thailand. The dinosaur was probably capable of moving on both two and four legs, standing upright to reach higher vegetation or dropping to all fours for ground-level feeding and faster locomotion.
The discovery of Siamodon has been particularly significant for understanding how ornithopod dinosaurs spread across ancient Asia. Its presence in Thailand during the Early Cretaceous suggests that the ancestors of the famous duck-billed dinosaurs were already diversifying across the continent much earlier than previously thought.
Siamodon possessed distinctive leaf-shaped teeth with prominent ridges that were well-adapted for processing tough plant material. Its jaw structure was more advanced than earlier ornithopods, showing early characteristics that would later be perfected in the duck-billed dinosaurs.
Siamodon likely lived in small herds, browsing on vegetation in the lush forests of Cretaceous Thailand. It probably used its sophisticated tooth batteries to process large quantities of plant material each day, spending much of its time feeding to support its substantial body size.
Siamodon was first described by Eric Buffetaut and Varavudh Suteethorn in 2011. The original fossils were discovered at Khok Kruat Formation, northeastern Thailand.