Plesiohadros Facts
| Diet | Herbivore |
| Height | 2.5m |
| Length | 6m |
| Weight | 1.5 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | Mongolia |

| Diet | Herbivore |
| Height | 2.5m |
| Length | 6m |
| Weight | 1.5 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | Mongolia |
Plesiohadros was a plant-eating ornithopod dinosaur that lived during the Late Cretaceous period, approximately 85.7 million years ago. This dinosaur inhabited the ancient landscapes of what is now southern Mongolia, where its fossils were discovered in the Alagteeg Formation at the Alag Teg locality.
As an ornithopod, Plesiohadros was part of a diverse group of herbivorous dinosaurs that includes the famous duck-billed hadrosaurs. However, Plesiohadros represents an earlier stage in ornithopod evolution, belonging to the hadrosauroid group - the broader family that would eventually give rise to the more advanced hadrosaurs. This makes it particularly important for understanding how these successful plant-eaters evolved their distinctive features.
The dinosaur was a substantial creature, measuring approximately 6 metres in length and standing about 2.5 metres tall at the hip. Like other ornithopods, it was primarily bipedal, walking on its powerful hind legs, though it may have occasionally dropped to all fours when feeding on low-growing vegetation. Its teeth and jaw structure were well-adapted for processing tough plant material, allowing it to thrive in the Cretaceous ecosystems of ancient Asia.
Plesiohadros is known from a relatively complete partial skeleton that includes crucial skull material, providing palaeontologists with valuable insights into the anatomy and lifestyle of these early hadrosauroids. The discovery has helped fill important gaps in our understanding of ornithopod evolution during the Campanian stage of the Late Cretaceous.
Plesiohadros possessed the characteristic features of early hadrosauroids, including a elongated skull with specialised teeth for grinding plant material. Its robust build and powerful hind limbs distinguished it as a substantial member of the ornithopod group, showing transitional characteristics between earlier ornithopods and the later duck-billed hadrosaurs.
As a herbivorous ornithopod, Plesiohadros likely spent much of its time foraging for vegetation, using its specialised teeth to process tough plant material. It probably lived in herds for protection against predators, and may have been capable of both bipedal and quadrupedal locomotion depending on the situation.
Plesiohadros was first described by Soki Hattori and colleagues in 2019. The original fossils were discovered at Alag Teg locality, Alagteeg Formation, southern Mongolia.