Amargasaurus the Sauropod with Spines

Amargasaurus vs Ceratosaurus

Amargasaurus was a smaller Sauropod dinosaur of the Early Cretaceous.  Small is relative though.  It was around 33 feet (10 meters) long and weighed 5,700 lbs.  That is a mass of 2,585 kg.  Of course that is tiny  compared to some Sauropods found in Argentina, but still, that is not exactly a kitten.
The most distinctive feature of Amargasaurus was a double row of sharp defensive spines from it's head clear to close to part of  its tail.

If a local Theropod or carnivorous dinosaur tried to take on a Amagasaurus those spines would have given him heart burn... Actually, it would have been like trying to bite the neck of a porcupine.  .  .. very painful for a predator to get a mouthful of sharp spines. 

Ceratosaurus lived near the same time as Amargasaurus.  Ceratosaurs may have been extinct before that time though.  Ceratosaurs were a Theropod of the Late Jurassic.  .   . but maybe some lived into the Early Cretaceous.  Also, I must admit, Ceratosaurs were found in what is now Portugal... and Amargasaurus lived in wlhat is now Argentina.