''Guanlong'' (冠龍) is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
proceratosaurid tyrannosauroid
Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent b ...
from the
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987.
In European lithostratigraphy, the name ...
of
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. The taxon was first described in 2006 by
Xu Xing ''et al.'', who found it to represent a new taxon related to ''
Tyrannosaurus
''Tyrannosaurus'' is a genus of large theropoda, theropod dinosaur. The species ''Tyrannosaurus rex'' (''rex'' meaning "king" in Latin), often called ''T. rex'' or colloquially ''T-Rex'', is one of the best represented theropods. ''Tyrannosa ...
''. The name is derived from
Chinese
Chinese can refer to:
* Something related to China
* Chinese people, people of Chinese nationality, citizenship, and/or ethnicity
**''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation
** List of ethnic groups in China, people of ...
, translating as "crown dragon". Two individuals are currently known, a partially complete adult and a nearly complete
juvenile. These specimens come from the
Oxfordian stage of the Chinese
Shishugou Formation
The Shishugou Formation () is a geological formation in Xinjiang, China.
Its strata date back to the Late Jurassic period. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Din ...
.
Discovery
![Guanlong](https://upload.wikimedia.org/wikipedia/commons/1/1b/Guanlong.jpg)
''Guanlong'' was discovered in the
Dzungaria
Dzungaria (; from the Mongolian language, Mongolian words , meaning 'left hand') is a geographical subregion in Northwest China that corresponds to the northern half of Xinjiang. It is thus also known as Beijiang, which means "Northern Xinjiang" ...
area of China by a joint expedition by scientists from the
Institute of Vertebrate Paleontology and Paleoanthropology The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name suggest ...
and
George Washington University
, mottoeng = "God is Our Trust"
, established =
, type = Private federally chartered research university
, academic_affiliations =
, endowment = $2.8 billion (2022)
, preside ...
, and named by
Xu Xing and others in 2006. ''Guanlong'' comes from the Chinese words for "crown", 冠, and "dragon", 龍, referring to the crest. The specific epithet (五彩), ''wucaii'' (Hanyu Pinyin: wǔcǎi), means "multicoloured" and refers to the colours of rock of the Wucaiwan (五彩灣, "5-colored bay", "multicolored bay"), the multi-hued badlands where the creature was found.
![Guanlong fossil](https://upload.wikimedia.org/wikipedia/commons/b/b6/Guanlong_fossil.jpg)
At present, ''Guanlong'' is known from two specimens, one discovered on top of the other, with three other individual theropod dinosaurs, in the Shishugou Formation. The
holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...
(
IVPP V14531) is a reasonably complete, partially articulated adult skeleton, and was the one on top. Another, immature specimen, the
paratype
In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Of ...
IVPP V14532, is known from fully articulated and nearly complete remains. It was presumed to have been trampled, after death, by the adult. The crest on the skull of the immature specimen is notably smaller and restricted to the forward portion of the snout, while the adult has a larger and more extensive crest. The crests of both specimens are thin, delicate structures that likely served as display organs, possibly for events like mating.
Description
![Guanlong SIZE](https://upload.wikimedia.org/wikipedia/commons/4/43/Guanlong_SIZE.png)
''Guanlong'' was a relatively small theropod, reaching in length and in body mass.
[Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages']
Supplementary Information
Its fossils were found in the
Shishugou Formation
The Shishugou Formation () is a geological formation in Xinjiang, China.
Its strata date back to the Late Jurassic period. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Din ...
dating to about 160 million years ago, in the
Oxfordian stage
The Oxfordian is, in the ICS' geologic timescale, the earliest age of the Late Jurassic Epoch, or the lowest stage of the Upper Jurassic Series. It spans the time between 163.5 ± 1.0 Ma and 157.3 ± 1.0 Ma (million years ago). The Oxfordia ...
of the
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987.
In European lithostratigraphy, the name ...
period,
92 million years before its well-known relative ''
Tyrannosaurus
''Tyrannosaurus'' is a genus of large theropoda, theropod dinosaur. The species ''Tyrannosaurus rex'' (''rex'' meaning "king" in Latin), often called ''T. rex'' or colloquially ''T-Rex'', is one of the best represented theropods. ''Tyrannosa ...
''. This bipedal
saurischia
Saurischia ( , meaning "reptile-hipped" from the Greek ' () meaning 'lizard' and ' () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithis ...
n
theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
shared many traits with its descendants, and also had some unusual ones, like a large crest on its head. Unlike later tyrannosaurs, ''Guanlong'' had three long fingers on its hands. Aside from its distinctive crest, it would have resembled its close relative ''
Dilong
''Dilong'' (; lit. "earth dragon") is a Chinese dragon name that is also used to mean "earthworm" in traditional Chinese medicine and '' Geosaurus'' in zoological nomenclature.
Dragon
In Chinese mythology, ''dilong'' "earth dragon" is one of ...
'', and like ''Dilong'' may have had a coat of primitive
feather
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier ...
s.
Classification
![Guanlong wucaii by durbed](https://upload.wikimedia.org/wikipedia/commons/c/ca/Guanlong_wucaii_by_durbed.jpg)
In a recent study, ''Guanlong'' was found to be in a clade with both ''
Proceratosaurus
''Proceratosaurus'' is a genus of carnivorous theropod dinosaur from the Middle Jurassic ( Bathonian) of England. ''Proceratosaurus'' was a small dinosaur, measuring in length and in body mass.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Mos ...
'' and ''
Kileskus
''Kileskus'' (meaning ''lizard'' in the Khakas language) is a genus of tyrannosauroid dinosaur known from partial remains found in Middle Jurassic (Bathonian stage) Itat Formation of Sharypovsky District, Krasnoyarsk Krai (Russia). Fossils r ...
''. Together they formed the family
Proceratosauridae
Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous.
Distinguishing features
Unlike the advanced tyrannosaurids but similar to primitive tyrannosauroids like ''Dilong ...
with a clade containing ''
Sinotyrannus
''Sinotyrannus'' (meaning "Chinese tyrant") is a genus of large basal tyrannosauroid dinosaur, known from a single incomplete fossil specimen including a partial skull, from the Early Cretaceous Jiufotang Formation of Liaoning, China. Specifi ...
'', ''
Juratyrant
''Juratyrant'' (meaning "Jurassic tyrant") is a tyrannosauroid dinosaur genus from the late Jurassic period (early Tithonian age) of England. The genus contains a single species, ''Juratyrant langhami'', which was once classed as a species of ''S ...
'' and ''
Stokesosaurus
''Stokesosaurus'' (meaning "Stokes' lizard") is a genus of small (around in length), carnivorous early tyrannosauroid theropod dinosaurs from the late Jurassic period of Utah, United States.
History
From 1960 onwards Utah geologist William L ...
''.
However, in 2014 another study was published, instead finding ''Stokesosaurus'' and ''Juratyrant'' outside the family, which only included ''Guanlong'', ''Proceratosaurus'', ''Kileskus'' and ''Sinotyrannus''.
Below is a simplified
cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
of the later analysis, from Fiorillo & Tykoski, 2014.
Paleobiology
![Guanlong wucaii head](https://upload.wikimedia.org/wikipedia/commons/7/74/Guanlong_wucaii_head.jpg)
The age of the two individuals were determined using a
histological
Histology,
also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...
analysis. The adult was shown to have matured at 7 years of age, and died at the age of 12. The juvenile died at 6, and was still growing. As the individuals are different ages, it can be seen some of the changes that happened during growth. In the juvenile, the crest is restricted to the snout, which is proportionally shorter. The orbit is also larger, the
hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "h ...
comparatively larger, the lower leg is longer, the
pubic bone
In vertebrates, the pubic region ( la, pubis) is the most forward-facing ( ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ...
has a less expanded end, and other features found in more derived
coelurosaur
Coelurosauria (; from Greek, meaning "hollow tailed lizards") is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs.
Coelurosauria is a subgroup of theropod dinosaurs that includes compsognathids, tyran ...
s and tyrannosauroids.
''Guanlong'' possessed a cranial crest, which may have been used for display. It is similar to those of ''
Dilophosaurus
''Dilophosaurus'' ( ) is a genus of theropod dinosaurs that lived in what is now North America during the Early Jurassic, about 193 million years ago. Three skeletons were discovered in northern Arizona in 1940, and the two best preserve ...
'' and ''
Monolophosaurus
''Monolophosaurus'' ( ; meaning "single-crested lizard") is an extinct genus of tetanuran theropod dinosaur from the Middle Jurassic Shishugou Formation in what is now Xinjiang, China.Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up ...
'', and like those it was highly
pneumatized. However, it was more delicate than in the other genera, and also proportionately larger and more elaborate. Structures in ''Dilophosaurus'' and ''Monolophosaurus'' have also been suggested to be for species recognition, but the more gracile crest of ''Guanlong'' is more likely for display purposes.
See also
*
Timeline of tyrannosaur research
This timeline of tyrannosaur research is a chronological listing of events in the history of paleontology focused on the tyrannosaurs, a group of predatory theropod dinosaurs that began as small, long-armed bird-like creatures with elaborate cr ...
References
External links
Pictures of newly discovered tyrannosaur(BBC News), "Oldest T. rex relative unveiled" 8 February 2006(''National Geographic''), "Tyrannosaur Trap" July 2008Accessed 17 June 2008
{{Taxonbar, from=Q131121
Proceratosaurids
Oxfordian life
Late Jurassic dinosaurs of Asia
Jurassic China
Fossils of China
Paleontology in Xinjiang
Fossil taxa described in 2006
Taxa named by Xu Xing