Sunday, July 10, 2011

Liaoceratops

      Liaoceratops is a newly discovered dinosaur supposed to be an early cousin to the horned ceratopsians. It was exposed in China by a team of American and Chinese scientists. Liaoceratops was much smaller than its later cousins, but offers a sight into the early evolution of one of the most enigmatic groups of dinosaurs.
Liaoceratops is rather small, weighing a predictable seven pounds and possessing only incomplete traces of horns and a frill, structures that characterized later ceratopsians. However, these skin help understand a major split in the evolution of ceratopsians. Long before the familiar Triceratops evolved in North America, the ceratopsian lineage split into two lines: the neoceratopsians, the main lineage that includes the familiar horned and frilled forms, and the psittacosaurids, a radiation of smaller, parrot-beaked dinosaurs.

    "Liaoceratops gives us a great window on the early development of horned dinosaurs and tells us that Triceratops and its relatives evolved from very small Asian ceratopsians. This small, prehistoric dinosaur is actually more interesting to science in many ways than its larger, more well-known relatives because it teaches us more about evolution. Basal dinosaurs are critical because they help us to tie dissimilar groups of dinosaurs together and map out evolutionary patterns," said Peter Makovicky, Curator of Dinosaurs at the Field Museum in Chicago and a co-author of the paper telling the dinosaur.

    "Liaoceratops establishes that this split occurred no later than the first part of the Cretaceous Period. Also, it indicates that ceratopsians acquired some of their distinctive features previous and more rapidly than was previously recognized," Makovicky said.

Ironically, the very small Liaoceratops may also help scientists appreciate the roles of horns and frills in ceratopsian dinosaurs. First thought of as offensive or suspicious organs, these structures are seen by many paleontologists today as show devices used in species recognition and to attract mates. Liaoceratops has a small horn opposite sideways under each of its eyes. As this arrangement is quite small and light, Makovicky believes that it was a display organ and had no purpose in defense.

Liaoceratops was exposed in the famous Liaoning Province of China, where several fossils of feathered dinosaurs have also been composed. These beds have also yielded fossil insects, fossils of ginkgo trees, and many other dinosaurs, counting the early troodontid Sinovenator, also described by Makovicky earlier this year. In the future, Makovicky hopes to continue his field works in the Liaoning Province.

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