| Diet | Herbivore |
| Height | 3m |
| Length | 8m |
| Weight | 3 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | Argentina |
Secernosaurus was a remarkable ornithopod dinosaur that lived approximately 72 million years ago during the Late Cretaceous period in what is now Argentina. This plant-eating dinosaur represents one of the most significant discoveries in South American palaeontology, as it was among the first duck-billed dinosaurs found on the continent. Measuring around 8 metres in length and standing about 3 metres tall at the hip, Secernosaurus was a substantial herbivore that roamed the ancient landscapes of Patagonia.
What makes Secernosaurus particularly fascinating is its unique geographical location. Whilst most of its ornithopod relatives lived in the northern continents of North America, Europe, and Asia, Secernosaurus and its close relatives made their home in South America. Scientists believe that the ancestors of Secernosaurus crossed into South America when a temporary land bridge formed between North and South America during the Late Cretaceous, allowing these dinosaurs to migrate southward and establish new populations.
Like other duck-billed dinosaurs, Secernosaurus possessed the characteristic broad, flattened snout that gave this group their common name. This specialised mouth structure was perfectly adapted for stripping vegetation and processing tough plant material. The dinosaur likely fed on ferns, conifers, and flowering plants that were abundant in the warm, humid climate of Late Cretaceous Argentina.
Secernosaurus represents an important piece of the puzzle in understanding how dinosaur populations spread across the globe during the Mesozoic era. Its presence in South America demonstrates the incredible ability of these animals to colonise new territories when geographical opportunities arose.
Secernosaurus had the characteristic duck-like bill of its family, with a broad, flattened snout ideal for cropping vegetation. It possessed the typical ornithopod body plan with powerful hind legs for bipedal locomotion and smaller forelimbs that could be used for quadrupedal movement when feeding.
Secernosaurus likely lived in herds, as evidenced by other members of its family, and would have migrated seasonally in search of fresh vegetation. It could switch between bipedal and quadrupedal locomotion depending on whether it was travelling or feeding near the ground.
Secernosaurus was first described by Rodolfo Coria in 1979. The original fossils were discovered at Bajo Barreal Formation, Chubut Province, Argentina.
