Simplify the following text for a Grade 12 native English-speaking person.
Original: Bonaparte also discovered or described a number of archosaurs and primitive birds ( such as Iberomesornis ) , and assisted with the study of other dinosaurs , like the Giganotosaurus carolinii .
Simplified: He also discovered or described a number of archosaurs and primitive birds ( such as Iberomesornis ) and has assisted with the study of other dinosaurs , like Giganotosaurus .