Hadrosaur

Many species, like Parasaurolophus , boasted elaborate hollow head crests. Research suggests these were used as "prehistoric trumpets" to produce low-frequency calls for communication. Performance (Behavior & Lifestyle):

They were the ultimate survivalists, inhabiting environments ranging from the Mexican desert to the chilly Arctic . hadrosaur

Their signature wide, flat snout was lined with a keratinous beak —perfect for cropping massive amounts of vegetation. hadrosaur