Othnielia was a small North American Hypsilophodontid, living 155-145 Million Years Ago. It
was around 2 metres long and 45-65 kilograms. This little herbivore would have been sociable, using bursts of high speed to evade the apex predators such as Allosaurus,and Torvosaurus. It was named for its finder, meaning 'Belonging to Othniel', for the American Palaeontologist Othniel Charles Marsh.
In Ballad of Big Al
In reality, this could happen, because Hypsilophodontid havn't any defenses.