The ever-growing horned dinosaur family has a new member: a heavily built, medium-dog-sized plant eater with an interesting corrugated texture on most of its skull. It’s called Hualianceratops wucaiwanensis, and unlike its Triceratops cousin, this dinosaur stood on its hind feet – and it didn’t actually have horns. The new genus and species – one of the oldest horned dinosaurs ever found – is described in PLOS ONE this week.
A team led by Fenglu Han from the China University of Geosciences described the new dinosaur after studying a fossilized partial skull and foot collected back in 2002 from the Upper Jurassic Shishugou Formation of the Junggar Basin in Xinjiang Province, northwestern China. A reconstruction of the 25-centimeter-long (10-inch-long) skull is pictured below.
The genus name combines “hualian,” which means ornamental face in Chinese, with “ceratops” for horned face in Greek, and it refers to the texture found on most of the skull. And “wucaiwan,” Chinese for five color bay, refers to the area where the specimen was discovered.
While horned dinosaurs of the suborder Ceratopsia are some of the best-studied herbivorous, beaked dinosaurs, their early evolution is still controversial and unclear, especially since the fossils of the oldest forms are often poorly preserved.
At about 160 million years old, Hualianceratops is the same age as the oldest-known horned dino, Yinlong downsi – though both are hornless. Yinlong was discovered by the same research team in 2002 as well. "Finding these two species in the same fossil beds reveals there was more diversity there than we previously recognized," study co-author Catherine Forster of George Washington University says in a statement. That means at least five ceratopsian lineages were present at the beginning of the Late Jurassic: Yinlong, Hualianceratops, Chaoyangsaurus and Xuanhuaceratops, Psittacosaurus, and Neoceratopsia. That last group went on to dominate in the Late Cretaceous.
F. Han et al., PLOS ONE 2015
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