Image: ¿ 2002 MICHAEL SKREPNICK/Courtesy of The Field Museum
The remains of a newly discovered dinosaur species that is a distant cousin of Triceratops have been discovered in China, scientists say. The hare-sized animals--dubbed Liaoceratops yanzigouensis after the region and province in which they were discovered--represent the smallest, oldest and most primitive neoceratops (the main line of horned dinosaurs) ever found. A report detailing the find appears in the current issue of the journal Nature.
Peter Makovicky of the Field Museum in Chicago and colleagues collected the fossils from 124- to 145-million-year-old rocks in the Yixian Formation in China, which has recently produced many intriguing fossil finds. The team uncovered two specimens, a juvenile skull and a nearly complete adult skull. They determined that Liaoceratops stood about one foot tall and measured less than three feet long. According to the report, the creature had a small horn facing sideways under each of its eyes and a short, thick frill that served to counteract contraction of the animal's large jaw muscles. It is unlikely, Makovicky notes, that the horns evolved for defense purposes. "Liaoceratops appears unable to protect itself against most predators, which would have included carnivorous dinosaurs and crocodiles," he says. "Instead, it probably relied on concealment or flight to defend itself."
Though not nearly so menacing as its well known cousin, Liaoceratops does shed new light on the evolution of horned dinosaurs (the ceratopsians). Millions of years ago, the group diverged into two lines, the neoceratopsians (which include Triceratops) and the psittacosaurids, or parrot-beaked dinosaurs. The researchers report that the new fossils establish that the split occurred no later than about 130 million years ago, during the earliest part of the Cretaceous Period, and that their distinctive features evolved more rapidly than previously thought. Says Makovicky, "Liaoceratops demonstrates that the large, spectacular species that grace many museum exhibits are descended from some very small ancestors."