Complex sentence: Also known as a "hadrosaur", this group of semi-quadrupedal herbivores are characterized by elaborate chewing mechanisms, similar to modern ungulates; and a crest on the top of their head, which may have been used for complex vocalizations.
Split into simpler sentences: Also known as hadrosaurs, these semi-quadrupedal herbivores are characterized by elaborate chewing mechanisms, similar to modern ungulates. Many also had a crest on the top of their head, which may have been used for complex vocalizations.