Liaoceratops
Encyclopedia
Liaoceratops, meaning "Liao Horned Face", is a ceratopsian dinosaur
believed to be an early relative of the horned ceratopsids. It lived in the early Cretaceous
, some 130 million years ago. It was discovered in China
by a team of American and Chinese scientists. Liaoceratops was much smaller than its later relatives, but offers a glimpse into the early evolution
of this group of dinosaurs.
Province of China, where several fossils of feathered dinosaurs have also been collected.
The type species
Liaoceratops yanzigouensis was in 2002 named and described by Xu Xing, Peter Makovicky, Wang Xiaolin, Mark Norell and You Hailu. The generic name is derived from Liaoning
and the Greek keras, "horn" and ops, "face". The specific name refers to the town Yanzigou.
The holotype IVPP V12738 has been found in the Yixian Formation
dating from the Berremian. These beds have also yielded fossil insects, fossils of ginkgo
trees, and many other dinosaurs, including the early troodontid
Sinovenator
, also described by Makovicky later in 2005.
"This area is yielding extremely important information on the evolution of dinosaurs, mammals, insects, and flowering plants. I hope to find even more primitive specimens than Liaoceratops," Peter Makovicky said.
The holotype consists of an almost complete skull. As paratype
specimen IVPP V12633 has been referred, the skull of a juvenile. In 2007 another skull, CAGS-IG-VD-002, of a even younger individual was referred. This lacked the skull roof, which has been explained as the result of a predator opening the braincase to eat the contents.
evolved in North America
, the ceratopsian lineage branched into two lines: the neoceratopsians, the main lineage that includes the recognizable horned and frilled forms, and of which Liaoceratops in 2002 was the most basal known member, and the Psittacosauridae
, a radiation of smaller, parrot-beaked dinosaurs.
"Liaoceratops gives us a great window on the early evolution of horned dinosaurs and tells us that Triceratops and its relatives evolved from very small Asian ceratopsians. This small, primitive dinosaur is actually more interesting to science
in many ways than its larger, more famous relatives because it teaches us more about evolution. Basal dinosaurs are critical because they help us to tie different 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 describing the dinosaur.
"Liaoceratops establishes that this split occurred no later than the earliest part of the Cretaceous
Period. Also, it indicates that ceratopsians acquired some of their distinctive features earlier and more rapidly than was previously recognized," Makovicky said.
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
believed to be an early relative of the horned ceratopsids. It lived in the early Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, some 130 million years ago. It was discovered in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
by a team of American and Chinese scientists. Liaoceratops was much smaller than its later relatives, but offers a glimpse into the early evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
of this group of dinosaurs.
Discoveries and naming
Liaoceratops was discovered in the famous LiaoningLiaoning
' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...
Province of China, where several fossils of feathered dinosaurs have also been collected.
The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
Liaoceratops yanzigouensis was in 2002 named and described by Xu Xing, Peter Makovicky, Wang Xiaolin, Mark Norell and You Hailu. The generic name is derived from Liaoning
Liaoning
' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...
and the Greek keras, "horn" and ops, "face". The specific name refers to the town Yanzigou.
The holotype IVPP V12738 has been found in the Yixian Formation
Yixian Formation
The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans 11 million years during the early Cretaceous period...
dating from the Berremian. These beds have also yielded fossil insects, fossils of ginkgo
Ginkgo
Ginkgo , also spelled gingko and known as the Maidenhair Tree, is a unique species of tree with no close living relatives...
trees, and many other dinosaurs, including the early troodontid
Troodontidae
Troodontidae is a family of bird-like theropod dinosaurs. During most of the 20th century, troodontid fossils were few and scrappy and they have therefore been allied, at various times, with many dinosaurian lineages...
Sinovenator
Sinovenator
Sinovenator is a genus of troodontid dinosaur from China. It is from the early Cretaceous Period. Two fossils were originally found in the Lujiatun Beds of the lower Yixian Formation in China, about 125 million years ago during the Aptian age.The type species, Sinovenator changii, was...
, also described by Makovicky later in 2005.
"This area is yielding extremely important information on the evolution of dinosaurs, mammals, insects, and flowering plants. I hope to find even more primitive specimens than Liaoceratops," Peter Makovicky said.
The holotype consists of an almost complete skull. As paratype
Paratype
Paratype is a technical term used in the scientific naming of species and other taxa of organisms. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany...
specimen IVPP V12633 has been referred, the skull of a juvenile. In 2007 another skull, CAGS-IG-VD-002, of a even younger individual was referred. This lacked the skull roof, which has been explained as the result of a predator opening the braincase to eat the contents.
Description and Classification
Liaoceratops is rather small, with a holotype skull length of 154 millimetres, weighing an estimated seven pounds and possessing only jugal horns and a small skull frill, lacking the orbital horns and true neck shield that characterized later ceratopsians. However, these features help understand a major split in the evolution of ceratopsians. Long before the familiar TriceratopsTriceratops
Triceratops is a genus of herbivorous ceratopsid dinosaur which lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 65 million years ago in what is now North America. It was one of the last dinosaur genera to appear before the great Cretaceous–Paleogene...
evolved in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, the ceratopsian lineage branched into two lines: the neoceratopsians, the main lineage that includes the recognizable horned and frilled forms, and of which Liaoceratops in 2002 was the most basal known member, and the Psittacosauridae
Psittacosauridae
The Psittacosauridae were a group of ceratopsian dinosaurs, which lived between 140.2 and 99.6 million years ago. The family Psittacosauridae was first named by American paleontologist Henry Fairfield Osborn in 1923...
, a radiation of smaller, parrot-beaked dinosaurs.
"Liaoceratops gives us a great window on the early evolution of horned dinosaurs and tells us that Triceratops and its relatives evolved from very small Asian ceratopsians. This small, primitive dinosaur is actually more interesting to science
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
in many ways than its larger, more famous relatives because it teaches us more about evolution. Basal dinosaurs are critical because they help us to tie different groups of dinosaurs together and map out evolutionary patterns," said Peter Makovicky, Curator of Dinosaurs at the Field Museum
Field Museum of Natural History
The Field Museum of Natural History is located in Chicago, Illinois, USA. It sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex known as the Museum Campus Chicago...
in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
and a co-author of the paper describing the dinosaur.
"Liaoceratops establishes that this split occurred no later than the earliest part of the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
Period. Also, it indicates that ceratopsians acquired some of their distinctive features earlier and more rapidly than was previously recognized," Makovicky said.