Bolong

Last updated

Bolong
Temporal range: Early Cretaceous, 125  Ma
O
S
D
C
P
T
J
K
Pg
N
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Clade: Neornithischia
Clade: Ornithopoda
Clade: Hadrosauriformes
Superfamily: Hadrosauroidea
Genus: Bolong
Wu, Godefroit & Hu, 2010
Species:
B. yixianensis
Binomial name
Bolong yixianensis
Wu, Godefroit & Hu, 2010
life restoration Bolong UDL.png
life restoration

Bolong (meaning "Bo's dragon") is a genus of iguanodontian dinosaur known from the Early Cretaceous-age Yixian Formation of western Liaoning Province, China. [1] It lived about 125 million years ago in the earliest Aptian. [1]

Contents

Discovery and naming

It was named by Wu Wen-hao, Pascal Godefroit and Hu Dong-yu in 2010. [1] The type species is Bolong yixianensis. [1] The genus name is derived from the names of the brothers Bo Hai-chen and Bo Xue, who helped uncover it, and the Mandarin word 龍 lóng "dragon". The specific epithet refers to the Yixian Formation where it was found. [1]

The holotype fossil, YHZ-001, consists of a nearly complete skeleton. [1]

In 2013 a second specimen (ZMNH-M8812) was described consisting of an almost complete skeleton of a very young animal. It was found by a farmer near the village of Xitaizhi in Inner Mongolia. [2]

Description

Bolong was a relatively small animal with an estimated length of four meters and a weight of 200 kilograms. The head is convex and fairly stocky with powerful mandibles. The teeth are relatively large. Autapomorphies that have been established are a cavity at the interface of the lacrimal bone, the maxilla, the backwards branch of the prefrontal bone, consisting of a front-to-rear depth cavity above the edges of the eye socket, the lower protrusion of the predentarium extending rearwardly parallel to the lower edge, the interface of the predentarium that occupies less than two-thirds of the height of the dentarium so that the front tip of the dentarium protrudes a third above the predentarium, and that the teeth in the maxilla have dental crowns of which the main ridge bends at the tip of the tooth. [1]

A second autapomorphy was identified based on the second specimen: the inside of the maxillary teeth are thickened and enclosed from the front and rear cutting edges and is divided in half by a striking vertical ledge. [2]

The gait of Bolong is disputed. The forelimb was fairly short, and the wrist bones were not fused together, suggesting that the forelimb was not well-adapted to bearing much weight, though the proportions of the distal forelimb are reminiscent of quadrupeds. [3] This suggests that Bolong was a facultative quadruped that spent much of its time walking bipedally, [3] which is also suggested by the relative proportions of the thigh and shin. [4] However, the hind foot was short and robust, more like fully quadrupedal dinosaurs than bipedal ones. [3] Very young individuals had a proportionally longer forelimb, typical of the proportions of quadrupedal animals. [2]

Phylogeny

The describers placed Bolong in Hadrosauroidea. It would have been one of the most basal hadrosauroids found in Asia. [1]

Related Research Articles

<i>Sinornithosaurus</i> Extinct genus of dinosaurs

Sinornithosaurus is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period of the Yixian Formation in what is now China. It was the fifth non–avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago.

<i>Psittacosaurus</i> Early Cretaceous dinosaur genus

Psittacosaurus is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 125 and 105 million years ago. It is notable for being the most species-rich non-avian dinosaur genus. Up to 12 species are known, from across China, Mongolia, Russia, and Thailand. The species of Psittacosaurus were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long filaments on the tail, similar to those of Tianyulong. Psittacosaurus probably had complex behaviours, based on the proportions and relative size of the brain. It may have been active for short periods of time during the day and night, and had well-developed senses of smell and vision.

<i>Yixianosaurus</i> Extinct genus of dinosaurs

Yixianosaurus is a maniraptoran theropod dinosaur genus from the Early Cretaceous of China.

<span class="mw-page-title-main">Iguanodontidae</span> Extinct family of dinosaurs

Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia.

<i>Amurosaurus</i> Extinct genus of dinosaurs

Amurosaurus is a genus of lambeosaurine hadrosaurid dinosaur found in the latest Cretaceous period of eastern Asia. Fossil bones of adults are rare, but an adult would most likely have been at least 6 metres (20 ft) long. According to Gregory S. Paul, it was about 8 metres (26 ft) long and weighed about 3,000 kilograms (6,600 lb).

<i>Sinovenator</i> Extinct genus of dinosaurs

Sinovenator is a genus of troodontid dinosaur from China. It is from the early Cretaceous Period.

<i>Liaoningosaurus</i> Extinct genus of dinosaurs

Liaoningosaurus is an unusual genus of basal ankylosaurid dinosaur from the Liaoning Province, China that lived during the Early Cretaceous in what is now the Yixian and Jiufotang Formation. The type and only species, Liaoningosaurus paradoxus, is known from more than 20 specimens, with some representing juveniles. It was named in 2001 by Xu, Wang and You.

<i>Jeholosaurus</i> Extinct genus of dinosaurs

Jeholosaurus is a genus of neornithischian dinosaur from the Early Cretaceous Period. It is thought to have been a herbivorous small ornithopod.

<span class="mw-page-title-main">Hadrosauroidea</span> Extinct clade of dinosaurs

Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosauridae, and all dinosaurs more closely related to them than to Iguanodon. Their remains have been recovered in Asia, Europe, Africa and the Americas. Many primitive hadrosauroids, such as the Asian Probactrosaurus and Altirhinus, have traditionally been included in a paraphyletic "Iguanodontidae". With cladistic analysis, the traditional Iguanodontidae has been largely disbanded, and probably includes only Iguanodon and perhaps its closest relatives.

<i>Graciliraptor</i> Extinct genus of dinosaurs

Graciliraptor is a genus of theropod dinosaur from the early Cretaceous Period. It is a microraptorine dromaeosaurid.

Yixianopterus is a pterodactyloid pterosaur genus from the Barremian-Aptian-age Lower Cretaceous Yixian Formation of Liaoning, China. It is known from a single specimen, holotype JZMP-V-12, housed at the Benxi Geological Museum. This specimen was modified before acquisition, with much of the skull being fabricated. The Jinggangshan bedding in which the specimen was found is basaltic with siliciclastic sediments. Many organisms associated with this layer of the Yixian Formation are aquatic, indicating a marine environment with much volcanic activity.

<span class="mw-page-title-main">Ankylopollexia</span> Extinct clade of dinosaurs

Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word, “ankylos”, mistakenly taken to mean stiff, fused, and the Latin word, “pollex”, meaning thumb. Originally described in 1986 by Sereno, a most likely synapomorphic feature of a conical thumb spine defines the clade.

Hexing is an extinct genus of basal ornithomimosaur dinosaur known from the Early Cretaceous of northeastern China. It contains a single species, Hexing qingyi.

Ningyuansaurus is a basal oviraptorosaurian dinosaur genus. It contains the single species Ningyuansaurus wangi, known from a fossil specimen from the Early Cretaceous Yixian Formation of Jianchang, western Liaoning Province, People's Republic of China. It is thought to be the basalmost species of oviraptorosaur, based on its long skull and a greater number of teeth in comparison to any other known oviraptorosaur. The generic name Ningyuansaurus is derived from Ningyuan, an ancient name for Xingcheng City. The specific name honors Wang Qiuwu, the private owner of the specimen who donated it for scientific study. The specimen is now in the Confuciusornis Museum in Xingcheng.

<i>Jianianhualong</i> Extinct genus of dinosaurs

Jianianhualong is a genus of troodontid theropod dinosaur from the Early Cretaceous of China. It contains a single species, Jianianhualong tengi, named in 2017 by Xu Xing and colleagues based on an articulated skeleton preserving feathers. The feathers at the middle of the tail of Jianianhualong are asymmetric, being the first record of asymmetrical feathers among the troodontids. Despite aerodynamic differences from the flight feathers of modern birds, the feathers in the tail vane of Jianianhualong could have functioned in drag reduction whilst the animal was moving. The discovery of Jianianhualong supports the notion that asymmetrical feathers appeared early in the evolutionary history of the Paraves.

<i>Daliansaurus</i> Extinct genus of dinosaurs

Daliansaurus is a genus of small troodontid theropod dinosaur, measuring approximately 1 metre long, from the Early Cretaceous of China. It contains a single species, D. liaoningensis, named in 2017 by Shen and colleagues from a nearly complete skeleton preserved in three dimensions. Daliansaurus is unusual in possessing an enlarged claw on the fourth digit of the foot, in addition to the "sickle claw" found on the second digit of the feet of most paravians. It also has long metatarsal bones, and apparently possesses bird-like uncinate processes. In the Lujiatun Beds of the Yixian Formation, a volcanically-influenced region with a cold climate, Daliansaurus lived alongside its closest relatives - Sinovenator, Sinusonasus, and Mei, with which it forms the group Sinovenatorinae.

<i>Liaoningvenator</i> Extinct genus of dinosaurs

Liaoningvenator is a genus of troodontid theropod dinosaur from the Early Cretaceous of China. It contains a single species, L. curriei, named after paleontologist Phillip J. Currie in 2017 by Shen Cai-Zhi and colleagues from an articulated, nearly complete skeleton, one of the most complete troodontid specimens known. Shen and colleagues found indicative traits that placed Liaoningvenator within the Troodontidae. These traits included its numerous, small, and closely packed teeth, as well as the vertebrae towards the end of its tail having shallow grooves in place of neural spines on their top surfaces.

Liaoningotitan is a genus of titanosauriform sauropod from the Early Cretaceous (Barremian) Yixian Formation in Liaoning, China.

<i>Wulong bohaiensis</i> Extinct species of dromaeosaurid dinosaur

Wulong is a genus of microraptorine dromaeosaurid dinosaurs from the Early Cretaceous (Aptian) Jiufotang Formation of China. The genus includes a single species, Wulong bohaiensis. The skeletal remains, which include preserved feathers, represent a juvenile.

<i>Changmiania</i> Genus of reptiles (fossil)

Changmiania is a genus of basal ornithopod dinosaur that lived in what is now China during the Early Cretaceous. It contains a single species, Changmiania liaoningensis.

References

  1. 1 2 3 4 5 6 7 8 Wu Wen-hao; Pascal Godefroit; Hu Dong-yu (2010). "Bolong yixianensis gen. et sp. nov.: A new Iguanodontoid dinosaur from the Yixian Formation of Western Liaoning, China". Geology and Resources. 19 (2): 127–133.
  2. 1 2 3 Zheng, Wenjie; Jin, Xingsheng; Shibata, Masateru; Azuma, Yoichi (4 March 2014). "An early juvenile specimen of Bolong yixianensis (Ornithopoda: Iguanodontia) from the Lower Cretaceous of Ningcheng County, Nei Mongol, China". Historical Biology. 26 (2): 236–251. Bibcode:2014HBio...26..236Z. doi:10.1080/08912963.2013.809347.
  3. 1 2 3 Wenhao, Wu; Godefroit, Pascal (2012). "Anatomy and relationships of Bolong yixianensis, an Early Cretaceous iguanodontoid dinosaur from Western Liaoning, China". In Godefroit, Pascal (ed.). Bernissart dinosaurs and Early Cretaceous terrestrial ecosystems. Indiana University Press. pp. 292–333. ISBN   978-0-253-00570-0.
  4. Xu, Xing; Tan, Qingwei; Gao, Yilong; Bao, Zhiqiang; Yin, Zhigang; Guo, Bin; Wang, Junyou; Tan, Lin; Zhang, Yuguang; Xing, Hai (2018). "A large-sized basal ankylopollexian from East Asia, shedding light on early biogeographic history of Iguanodontia". Science Bulletin. 63 (9): 556–563. Bibcode:2018SciBu..63..556X. doi:10.1016/j.scib.2018.03.016. ISSN   2095-9273. PMID   36658842.