Jingszo !

The duck-billed dinosaur Parasaurolophus is distinctive for its prominent crest, which some scientists have suggested served as a kind of resonating chamber to produce low-frequency sounds. Nobody really knows what Parasaurolophus sounded like, however. Hongjun Lin of New York University is trying to change that by constructing his own model of the dinosaur's crest and its acoustical characteristics.

It's that distinctive crest that has most fascinated scientists over the last century, particularly its purpose.

Past hypotheses have included its use as a snorkel or as a breathing tube while foraging for food; as an air trap to keep water out of the lungs; or as an air reservoir so the dinosaur could remain underwater for longer periods.

Other scientists suggested the crest was designed to help move and support the head or perhaps used as a weapon while combating other Parasaurolophus.

All of these, plus a few others, have largely been discredited.