T. rex and Triceratops are among the best-studied dinosaurs of all time. How much more can we learn? Surprisingly, more than we ever thought. Famed paleontologist Jack Horner and his colleagues are challenging the long held belief that young dinosaurs looked like miniature versions of their parents. Instead they may have looked so different that scientists assumed juveniles and adults were separate species. Even a young T. rex it would be hard to recognize. The transformations from childhood to adulthood were so dramatic that Horner suspects that up to a third of all dinosaur species may vanish in cases of mistaken identity. In their place were developing a new understanding of the complexity of dinosaur lives and learning new reasons for some of the dinosaurs' strangest features like horns lumps, bumps, and dome-heads.
Clues to why dinosaurs underwent such dramatic physical changes may be found in their closest living relatives—birds experts say. Hornbills, for example, don't sport their distinctive helmet-like head casque (see hornbill picture) until they are about three-quarters grown. Like deer antlers, the casque helps other animals discern between mature adults and juveniles.
In the same way, dinosaurs' changing appearances might have also promoted visual communication.For example head knobs or horns, likely paired with color variations, may have created unmistakable visual displays that made sure members of a species recognized one another.They may also have identified dinosaurs as male or female and marked them as mate-seeking breeders or juveniles in need of protection.
Regardless of what some political types might try to tell you about there being "no more debate" when it comes to certain areas of scientific inquiry, in science, the jury is always out...
Read the entire article here: A Third of Dinosaur Species Never Existed?