"Thyreos are large herbivores that wander through the island's forest to feed on peculiar roots and bunches of ferns. Other times they are wallowing in shallow pools and chewing on aquatic plants in small groups.
Despite how calm they may seem, Thyreos have a bad habit of smashing anything with their tail if approached, often killing or crippling whatever dared to get near. This goes doubly so for mother Thyreos who defend their young with extreme prejudice.
The notably large plates along the back act as a display that makes any predator wary of the Thyreos's size, as well as to impress or threaten other Thyreos. Thyreos only start to develop these plates after a month of being born, when they are already getting too big for their mother to carry them in her mouth. The role of the plates in early life is to generally make them too hard to swallow for most predators, also so the mother can spot them in the brush.
Interestingly, Thyreos are crocodilians that have developed into primarily terrestrial herbivores. It is currently unknown if they share an origin with the salt water crocodile descended Ruptorsaurs, or if they descend from an ancient line of crocodylomorphs."
