CollectA AmargasaurusCollectA Amargasaurus CollectA model 88220 Product Dimensions: 16 x 3. 5 x 5. 5 cm Age: 3 years and up Amargasaurus was a sauropod dinosaur that lived during the Early Cretaceous period, about 129 to 122 million years ago, in what is now Argentina. It is known for its distinctive double row of tall, spiky neural spines running along its neck and back. These spines could have been used for display, to deter predators, or to regulate body temperature.