Ammosaurus Facts
| Diet | Herbivore |
| Height | 1.2m |
| Length | 4m |
| Weight | 500 kg |
| Environment | Land |
| Era | Jurassic |
| Period | Early Jurassic |
| Type | Sauropod |
| Location | North America |

| Diet | Herbivore |
| Height | 1.2m |
| Length | 4m |
| Weight | 500 kg |
| Environment | Land |
| Era | Jurassic |
| Period | Early Jurassic |
| Type | Sauropod |
| Location | North America |
Ammosaurus, meaning 'sand lizard', was an early sauropod dinosaur that lived during the Early Jurassic period, approximately 201 million years ago. Originally described as a separate genus, palaeontologists now consider Ammosaurus to be the same animal as Anchisaurus, making it what scientists call a 'junior synonym'. This fascinating creature represents one of the earliest members of the sauropod lineage that would eventually give rise to the largest land animals that ever lived.
Living in what is now the northeastern United States, Ammosaurus inhabited a landscape of river plains and forests during the early Jurassic. At around 4 metres long and standing about 1.2 metres tall at the hip, it was considerably smaller than its later sauropod relatives like Brontosaurus. Weighing approximately half a tonne, this early sauropod had a relatively long neck and tail, though not as extremely elongated as later species.
As a herbivore, Ammosaurus fed on the abundant plant life of its time, including ferns, conifers, and cycads. Its teeth were leaf-shaped and suitable for cropping vegetation, though it likely swallowed stones to help grind up tough plant material in its stomach. The creature could probably rear up on its hind legs to reach higher vegetation, a behaviour that would become characteristic of many later sauropods.
The fossils of Ammosaurus were discovered in the red sandstones of the Portland Formation in Connecticut, providing valuable insights into the early evolution of the sauropod group during a crucial period in dinosaur history.
Ammosaurus had a moderately long neck and tail compared to its body size, with relatively robust limbs. Its head was small in proportion to its body, and it possessed leaf-shaped teeth adapted for processing plant material.
Ammosaurus likely lived in small herds and could rear up on its hind legs to browse on higher vegetation. It probably used gastroliths (stomach stones) to help digest tough plant material, a behaviour common among early sauropods.
| Phylum | Chordata |
| Class | Saurischia |
| Family | Anchisauridae |
| Genus | Ammosaurus |
Ammosaurus was first described by Othniel Charles Marsh in 1889. The original fossils were discovered at Portland Formation, Connecticut, USA.