Kentrosaurus is a genus of stegosaur from the Upper Jurassic epoch of Africa. It was a fairly small species, reaching up to 5 meters in length and weighed about 1.500 kg. On its back it had two rows of small plates that were probably used for display. Its tail was armed with multiple sets of conical spines which were probably used for defence against predators. It was also able to make very tight turns due to the center of its mass laying just before its hips. Combined, these traits made sure that predators weren't able to take down an individual that easily.
The genus of Kentrosaurus is only known from a singular species: K. aethiopicus. Many fossils of this species have been found in the Tendaguru formation of Tanzania (Africa); the remains of about 70 individuals have been found here! These numbers make scientists believe that Kentrosaurus lived in herds for protection.
Mallison, H. (2011). Defense capabilities of Kentrosaurus aethiopicus Hennig, 1915. Palaeontologia Electronica, 14(2), 1-25.