Longest dinosaur horns
Who
Triceratops, Torosaurus, Coahuilaceratops
What
1.15 metre(s)
Where
United States ()
When

The longest horns of any dinosaur are the paired brow horns borne above the eyes by three genera of ceratopsian (horned) dinosaur – the North American Triceratops, the North American Torosaurus, and the Mexican Coahuilaceratops. Each of these horns is estimated to have measured up to 1.2 m (4 ft) long. Perhaps the most sizeable exhibited specimen in relation to horn length is a Triceratops specimen displayed at the Museum of the Rockies in Montana, USA, and known informally as Yoshi's Trike, whose brow horns each measure 1.15 m (3.77 ft) long. Moreover, this specimen is believed to have died while still incompletely grown, so, had it survived, its horns may well have grown even longer.


Down through the decades since their first fossils were discovered, a range of different functions have been proposed for the brow horns of ceratopsian dinosaurs. However, the most popular theory is that they were used for courtship displays, to attract females directly and also for males to joust with each other in order to win the attention of females, just like modern-day male deer do with their antlers. Alternatively, or possibly even additionally, they may have been used for direct combat with attacking predators, such as theropod dinosaurs like Tyrannosaurus rex, which existed alongside Triceratops during the Late Cretaceous, around 70 million years ago.