The dry, windy plains of Patagonia, in South America, are as beautiful as they are barren. But did they once teem with life? Paleontologists (scientists who study fossils) have proved that this rugged region is a rich repository of reptile remains. Campus out in the filed for weeks at a time, these scientific scavengers search with unflagging curiosity and dedication for new clues to some of the cryptic mysteries of the long-extinct dinosaurs. Their tools are rock hammers, brushes, and hand lenses.
What is the meaning of scavengers as it is used in the paragraph above.