This dinosaur may have had a body like a duck’s

If I understand this correctly, this Natovenator polydontus was about the size of a duck and it had a similar lifestyle to moderon day waterfowl, though without flight. Also, it seems that Natovenator polydontus was of a lineage rather distant from avians (birds). It's pictured as having something like feathers. Last point, some non-avian dinosaurs had hollow bones just as the pterosaurs did and as birds do.