| Diet | Herbivore |
| Height | 4m |
| Length | 15m |
| Weight | 12 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Sauropod |
| Location | Argentina |
Clasmodosaurus was a sauropod dinosaur that lived during the Late Cretaceous period in what is now Argentina. As a member of the titanosaurian group, it would have been a massive, long-necked herbivore that dominated the South American landscape around 100 to 94 million years ago. However, our knowledge of this sauropod remains quite limited, as it is known only from five fossilised teeth discovered in the Mata Amarilla and Cerro Fortaleza formations of Patagonia.
Like other sauropods, Clasmodosaurus would have been a quadrupedal giant with an enormously long neck, allowing it to reach vegetation high in the tree canopy that other dinosaurs couldn't access. Its teeth suggest it was well-adapted for processing tough plant material, including conifers, ferns, and cycads that were common during the Cretaceous period. The creature likely used its pencil-like teeth to strip leaves and needles from branches rather than chewing, swallowing plant matter whole to be processed in its massive gut.
Being a titanosaurian sauropod, Clasmodosaurus would have shared characteristics with other South American giants like Argentinosaurus and Dreadnoughtus. These dinosaurs were among the largest land animals ever to have lived, and Clasmodosaurus was likely no exception. However, the limited fossil evidence makes it challenging to determine its exact size, body proportions, or unique features that might have distinguished it from its relatives.
The discovery of Clasmodosaurus adds to our understanding of titanosaurian diversity in South America during the mid-Cretaceous period, though much more fossil evidence would be needed to fully understand this mysterious giant.
Clasmodosaurus is diagnosed by a unique combination of dental characteristics, though the specific details are difficult to determine from the limited tooth fossils. As a titanosaurian sauropod, it would have had the typical pencil-like teeth adapted for stripping vegetation.
Like other sauropods, Clasmodosaurus likely lived in herds and spent most of its time feeding on vegetation at various heights. Its enormous size would have provided protection from predators, though juveniles may have been vulnerable to large theropods.
Clasmodosaurus was first described by Paulina Carabajal and colleagues in 2019. The original fossils were discovered at Mata Amarilla Formation and Cerro Fortaleza Formation, Argentina.
