[D] Guanlong wucaii [Su] [sG] [T]
Describer
Xu, Clark, Forster, Norell, Ericson, Eberth, Jia and Zhao, 2006
Time
Jurassic Late Oxfordian
Classification
Saurischia Theropoda Tyrannosauria Tyrannosauroidea Proceratosauridae
Diet
Carnivore
Fossilsite
Shishugou Formation, Junggar Basin, Wucaiwan area, Xinjiang, China
Info
Genus - Typespecies - Skull
Xing Xu, James M. Clark, Catherine A. Forster, Mark A. Norell, Gregory M. Erickson, David A. Eberth, Chengkai Jia and Qi Zhao. (2006). A basal tyrannosauroid dinosaur from the Late Jurassic of China. Nature 439: 715-718
Abstract
The tyrannosauroid fossil record is mainly restricted to Cretaceous sediments of Laurasia, although some very fragmentary Jurassic specimens have been referred to this group. Here we report a new basal tyrannosauroid, Guanlong wucaii gen. et sp. nov., from the lower Upper Jurassic of the Junggar Basin, northwestern China.
Guanlong wucaii is one of the oldest known tyrannosauroid and shows several unexpectedly primitive pelvic features. Nevertheless, the limbs of Guanlong wucaii share several features with derived coelurosaurs, and it possesses features shared by other coelurosaurian clades.
This unusual combination of character states provides an insight into the poorly known early radiation of the Coelurosauria. Notably, the presumed predatory Guanlong wucaii has a large, fragile and highly pneumatic cranial crest that is among the most elaborate known in any non-avian dinosaur and could be comparable to some classical exaggerated ornamental traits among vertebrates.
Etymology. The generic name is derived from the Chinese Guan (crown) and long (dragon); the specific name is from the Chinese wucai (five colours), which refers to the rich colours of rocks that produced the specimens.
Holotype
IVPP (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing) V14531 is a partly articulated skeleton preserving most of the elements.
Referred material
IVPP V14532 is much smaller than the holotype and is a fully articulated, nearly complete skeleton.
Locality and horizon
Oxfordian upper part of the Shishugou Formation (formerly considered a separate \\\\\\\"Wucaiwan Formation\\\\\\\")
Carr, T. (2006) Is Guanlong a Tyrannosauroid or a subadult Monolophosaurus? JVP 26(3) Abstracts pp.48
Guanlong wucaii is a purported Late Jurassic basal tyrannosauroid from the Shishugou Formation of northwestern China. Guanlong bears a tall and fenestrated nasal crest that extends along the top of the snout, as in Monolophosaurus jiangi, a carnosaur that is about twice the size as Guanlong, from a lower level in the same unit.
The original cladistic analysis of Guanlong used a data matrix relevant to resolving the relationships among basal theropods, which reconstructed it as a basal tyrannosauroid. However, the similarities shared between Guanlong and Monolophosaurus jiangi in the crest prompted a test of the original hypothesis using a data matrix based on characters relevant for resolving ingroup relationships of Tyrannosauroidea.
The data matrix includes 201 characters and 34 theropod species. The matrix was analyzed in PAUP* 4.0b under a heuristic search; Guanlong was reconstructed as a carnosaur, and as the sister species of Monolophosaurus. This relationship is supported by the shape of the rostral ramus of the maxilla; a sagittal, elongate, pneumatic, and fenestrate crest along the top of the snout; and a foramen in the pubic process of the ischium.
Monolophosaurus jiangi is distinguished from Guanlong by a longer crest that includes the premaxilla and lacrimal, a rostrally-positioned maxillary fenestra, a deep maxilla, a long jugal process of the quadratojugal, and a subocular process on the postorbital. Guanlong is distinguished from Monolophosaurus by a wide snout tip, short squamosal process of the postorbital, a concave orbital margin of the postorbital, a cornual process on the jugal, the antorbital fossa is deeply excavated into the jugal, absence of a caudal surangular foramen, fewer dentary teeth, apneumatic cervical centra, presence of a rostrodorsal notch in the ilium, and the presence of a pubic tubercle.
These results suggest two alternative hypotheses for Guanlong: it is either the sister taxon, or it is a subadult, of Monolophosaurus jiangi.
Xu, Clark, Forster, Norell, Ericson, Eberth, Jia and Zhao, 2006
Time
Jurassic Late Oxfordian
Classification
Saurischia Theropoda Tyrannosauria Tyrannosauroidea Proceratosauridae
Diet
Carnivore
Fossilsite
Shishugou Formation, Junggar Basin, Wucaiwan area, Xinjiang, China
Info
Genus - Typespecies - Skull
Xing Xu, James M. Clark, Catherine A. Forster, Mark A. Norell, Gregory M. Erickson, David A. Eberth, Chengkai Jia and Qi Zhao. (2006). A basal tyrannosauroid dinosaur from the Late Jurassic of China. Nature 439: 715-718
Abstract
The tyrannosauroid fossil record is mainly restricted to Cretaceous sediments of Laurasia, although some very fragmentary Jurassic specimens have been referred to this group. Here we report a new basal tyrannosauroid, Guanlong wucaii gen. et sp. nov., from the lower Upper Jurassic of the Junggar Basin, northwestern China.
Guanlong wucaii is one of the oldest known tyrannosauroid and shows several unexpectedly primitive pelvic features. Nevertheless, the limbs of Guanlong wucaii share several features with derived coelurosaurs, and it possesses features shared by other coelurosaurian clades.
This unusual combination of character states provides an insight into the poorly known early radiation of the Coelurosauria. Notably, the presumed predatory Guanlong wucaii has a large, fragile and highly pneumatic cranial crest that is among the most elaborate known in any non-avian dinosaur and could be comparable to some classical exaggerated ornamental traits among vertebrates.
Etymology. The generic name is derived from the Chinese Guan (crown) and long (dragon); the specific name is from the Chinese wucai (five colours), which refers to the rich colours of rocks that produced the specimens.
Holotype
IVPP (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing) V14531 is a partly articulated skeleton preserving most of the elements.
Referred material
IVPP V14532 is much smaller than the holotype and is a fully articulated, nearly complete skeleton.
Locality and horizon
Oxfordian upper part of the Shishugou Formation (formerly considered a separate \\\\\\\"Wucaiwan Formation\\\\\\\")
Carr, T. (2006) Is Guanlong a Tyrannosauroid or a subadult Monolophosaurus? JVP 26(3) Abstracts pp.48
Guanlong wucaii is a purported Late Jurassic basal tyrannosauroid from the Shishugou Formation of northwestern China. Guanlong bears a tall and fenestrated nasal crest that extends along the top of the snout, as in Monolophosaurus jiangi, a carnosaur that is about twice the size as Guanlong, from a lower level in the same unit.
The original cladistic analysis of Guanlong used a data matrix relevant to resolving the relationships among basal theropods, which reconstructed it as a basal tyrannosauroid. However, the similarities shared between Guanlong and Monolophosaurus jiangi in the crest prompted a test of the original hypothesis using a data matrix based on characters relevant for resolving ingroup relationships of Tyrannosauroidea.
The data matrix includes 201 characters and 34 theropod species. The matrix was analyzed in PAUP* 4.0b under a heuristic search; Guanlong was reconstructed as a carnosaur, and as the sister species of Monolophosaurus. This relationship is supported by the shape of the rostral ramus of the maxilla; a sagittal, elongate, pneumatic, and fenestrate crest along the top of the snout; and a foramen in the pubic process of the ischium.
Monolophosaurus jiangi is distinguished from Guanlong by a longer crest that includes the premaxilla and lacrimal, a rostrally-positioned maxillary fenestra, a deep maxilla, a long jugal process of the quadratojugal, and a subocular process on the postorbital. Guanlong is distinguished from Monolophosaurus by a wide snout tip, short squamosal process of the postorbital, a concave orbital margin of the postorbital, a cornual process on the jugal, the antorbital fossa is deeply excavated into the jugal, absence of a caudal surangular foramen, fewer dentary teeth, apneumatic cervical centra, presence of a rostrodorsal notch in the ilium, and the presence of a pubic tubercle.
These results suggest two alternative hypotheses for Guanlong: it is either the sister taxon, or it is a subadult, of Monolophosaurus jiangi.