From horntip to tail tip, it was about four metres long.
All ceratopsids have greatly enlarged nose regions, but Nasutoceratops is a champion.
Why, though, is unclear.
"The jumbo-sized schnoz of Nasutoceratops likely had nothing to do with a heightened sense of smell, since olfactory receptors occur further back in the head, adjacent to the brain," said Scott Sampson of the University of Utah.
"The function of this bizarre feature remains uncertain."
His colleague, Mark Loewen, said the dino's "amazing horns" "were most likely used as visual signals of dominance and, when that wasn't enough, as weapons for combating rivals".
The evidence provides more tantalising details about a 27-million-year spell in the Late Cretaceous when high temperatures melted global icecaps and forced up sea levels, says the study.
The ocean spilled into central North America, leaving two big land masses riding above a warm, shallow sea.
One, in the east, has been called Appalachia, while an Australia-sized landmass in the west, running from Alaska all the way down to Mexico, has been named Laramidia, according to a 17-year-old theory.
Laramidia was a stomping ground for dinosaurs. Tyrannosaurs, hadrosaurs, dromaeosaurids and troodoontids have all been found there. Alberta, Montana and Alaska have provided rich finds of ceratopses.
The unusual shape of N. titusi shows how giant species differentiated to fit in to a local habitat, a process called provincialism, says the study.
The research is published in the British journal, Proceedings of the Royal Society.
- AFP
