Scientists analysing fossil records have discovered a new three-horned dinosaur, dating back 66 to 80 million years, that sported a hoodie-like growth on the back of its head.

The giant creature may be the oldest known cousin of Triceratops and Torosaurus -- the best-known horned dinosaurs -- yet, researchers say.

Judiceratops tigris has been identified based on fossils from north central Montana, further underscoring the diversity of large, plant-eating horned dinosaurs among the fauna of western North America 66 to 80 million years ago.

By now, fossil remains of at least 18 closely related dinosaurs from the region have been identified as distinct species, and Yale researcher Nicholas Longrich expects others will be discovered.

“We keep finding new species, because cerotopsids -- horned dinosaurs -- evolved so rapidly,” said Longrich, who identified the latest addition to the family.

“These species show up for just a couple million years, or even a far shorter time, before another species replaces it.

As you move up into younger rocks or down into older rocks, you get new species and no longer see the old ones. There was a lot of turnover,” said Longrich.

Identified by analysis of skull fragments belonging to four previously collected specimens in the Peabody’s collection, Judiceratops lived during the late Cretaceous era, about 78 million years ago, or 12 million years before the more familiar Triceratops and Torosaurus.

Judiceratops is the earliest known member of the chasmosaurines, a group of horned dinosaurs characterised by an enlarged frill on the back of the skull. It does not appear to be a direct ancestor of Triceratops and Torosaurus, Longrich said.

Judiceratops was likely a large plant-eating dinosaur that fed on low-growing vegetation, such as ferns, like other members of its family. It had two large horns over the brow and a smaller horn on its nose.

The three-horned Judiceratops differs from all other horned dinosaurs in the shape and arrangement of the scallops on the edge of the frill, which are large and triangular toward the front, and low and blunt toward the back.

The ornate frills might have been a way for the dinosaurs to attract mates and intimidate rivals, Longrich speculates, as some birds (modern dinosaurs) do through elaborate plumage or song.

“These are very bold, conspicuous display structures,” Longrich said of the frills, which might also have served a defensive purpose.

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