The name of Sordes is always brought up when scientists debate whether pterosaurs were warm-blooded or cold-blooded. One fossil specimen of Sordes discovered in 1971 included impressions that looked like a thick, furry coat over its body. Such a covering of hair would have helped Sordes keep warm during long flights. Even the name Sordes means "shabby" or "filthy," referring to its hairy body. A coat of hair does not necessarily mean that this pterosaur was warm-blooded, though. It's possible that some prehistoric reptiles used fur to maintain body temperature, just like mammals do today.