Kaijiangosaurus

Last updated

Kaijiangosaurus
Temporal range: Middle Jurassic Bathonian–Callovian
O
S
D
C
P
T
J
K
Pg
N
Kaijiangosaurus SW.png
Speculative life restoration based on other theropods
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Tetanurae
Genus: Kaijiangosaurus
He, 1984
Type species
Kaijiangosaurus lini
He, 1984

Kaijiangosaurus (meaning "Kiijiang lizard") is a genus of carnivorous tetanuran theropod dinosaur from the Middle Jurassic of China. In 1984 He Xinlu named and described the type species Kaijiangosaurus lini. The generic name refers to the River (jiang) Kai. The specific name honours the paleontologist Lin Wenqiu. [1]

Contents

Discovery

The holotype specimen, CCG 20020, was discovered in Sichuan, in a layer of the Xiashaximiao Formation dating from the Bathonian-Callovian. The specimen consists of a fragmentary skeleton lacking the skull. The holotype proper contains the intercentrum of the atlas and the third to ninth neck vertebrae. Other elements have been designated as a paratype, including fragmentary remains of the skull, nine teeth, elements of the pectoral girdle, a forelimb, and a hindlimb. Another paratype is the thighbone of a probably smaller individual. [1] Holtz et al. (2004) mentioned much more complete specimens, but they are undescribed.[ citation needed ] There have been doubts about the validity of Kaijiangosaurus. It has been suggested that it should be regarded as a synonym of Gasosaurus , which was found in the same strata as Kaijiangosaurus, the Lower Shaximiao Formation, or of Xuanhanosaurus .[ citation needed ]

Description

Kaijiangosaurus had a length of about five metres. He mentioned some diagnostic traits. The jugal is straight-edged at the front, deeper at the rear. The teeth are of the megalosaurid type. Their leading edge has only few serrations, near the tip. The cervicals are short, wide and narrow in the middle. The front cervicals have spines with a concave trailing edge. These neck vertebrae are about as wide as they are long; their spines are low and wide. The centra of the rear cervical are concave at their back; their spines are long and narrow. The dorsals are platycoelous and have smooth sides lacking pleurocoels. The front tail vertebrae are also platycoelous, with a flat front and concave rear; the rear caudals are amphicoelous. The tail vertebrae have flat undersides without a midline groove. The scapula is rather straight with only a relative constriction at the lower end and a light expansion at the upper end. The coracoid is oval and has a thick ridge at the upper outer side. With the humerus, the deltopectoral crest is triangular; the shaft has an oval cross-section. The ulna is short and expanded at both ends. The three claws of the hand are strongly curved. Both ends of the thighbone are expanded; the neck is somewhat directed to the rear. The lesser trochanter is low, with a triangular profile. The middle metatarsals are not fused, nor is the third metatarsal constricted at the top. [1]

Classification

He originally placed Kaijiangosaurus in the Megalosauridae. [1] Modern analysis suggests it is a basal member of the Tetanurae, or perhaps the Averostra. [2] Due to the fragmentary nature of the remains, it is uncertain what type of tetanuran theropod it is, though it may be a primitive carnosaur. [3]

Related Research Articles

<i>Dilophosaurus</i> Genus of theropod dinosaur from Early Jurassic period

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 preserved were collected in 1942. The most complete specimen became the holotype of a new species in the genus Megalosaurus, named M. wetherilli by Samuel P. Welles in 1954. Welles found a larger skeleton belonging to the same species in 1964. Realizing it bore crests on its skull, he assigned the species to the new genus Dilophosaurus in 1970, as Dilophosaurus wetherilli. The genus name means "two-crested lizard", and the species name honors John Wetherill, a Navajo councilor. Further specimens have since been found, including an infant. Footprints have also been attributed to the animal, including resting traces. Another species, Dilophosaurus sinensis from China, was named in 1993, but was later found to belong to the genus Sinosaurus.

<i>Gasosaurus</i> Extinct genus of reptiles

Gasosaurus is a genus of tetanuran theropod that lived approximately 171.6 to 161.2 million years ago during the middle of the Jurassic Period. The name "Gasosaurus" is derived from the English "gasoline" and the Greek σαῦρος. Only one species is currently recognised, G. constructus, from which the specific name honours the gasoline company that found the Dashanpu fossil quarry in Sichuan Province, China, now named as the Lower Shaximiao Formation.

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

Monolophosaurus is a genus of tetanuran theropod dinosaur from the Middle Jurassic Shishugou Formation in what is now Xinjiang, China. It was named for the single crest on top of its skull. Monolophosaurus was a mid-sized theropod at about 5 metres long.

Chuandongocoelurus is a genus of carnivorous tetanuran theropod dinosaur from the Jurassic of China.

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

Condorraptor is an extinct genus of megalosauroid theropod dinosaur. Its genus name means 'robber from Cerro Condor', referencing a nearby village, while its species name, currumili, is named after Hipolito Currumil, the landowner and discoverer of the locality. It was among the earliest large South American theropods, having been found in Middle Jurassic strata of the Cañadón Asfalto Formation in the Cañadón Asfalto Basin of Argentina. The type species, described in 2005, is Condorraptor currumili. It is based on a tibia, with an associated partial skeleton that may belong to the same individual. Initially described as a basal tetanuran, Benson (2010) found it to be a piatnitzkysaurid megalosauroid and the sister taxon of Piatnitzkysaurus, a finding supported by later studies.

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

Sinusonasus is a genus of dinosaurs from the Early Cretaceous Period, recovered from the Yixian Formation. It lived in what is now the Liaoning Province of China. Sinusonasus was a theropod, specifically a troodontid dinosaur.

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

Dubreuillosaurus is a genus of carnivorous dinosaur from the middle Jurassic Period. It is a megalosaurid theropod. Its fossils were found in France. The only named species, Dubreuillosaurus valesdunensis, was originally described as a species of Poekilopleuron, Poekilopleuron? valesdunensis, which is still formally the type species of the genus. It was later renamed Dubreuillosaurus valesdunensis when, in 2005, Allain came to the conclusion that it was not part of the genus Poekilopleuron. Its type specimen, MNHN 1998-13, is only rivalled in the number of preserved elements in this group by that of Eustreptospondylus. Dubreuillosaurus is considered to be the sister species of Magnosaurus. It did not show signs of insular dwarfism even though it was uncovered on an island.

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

Spinostropheus is a genus of small carnivorous ceratosaurian theropod dinosaur that lived in the Middle Jurassic period and has been found in the Tiouraren Formation, Niger. The type and only species is S. gautieri.

Noasauridae Extinct family of dinosaurs

Noasauridae was a family of diverse theropod dinosaurs from the group Ceratosauria. They were closely related to the short-armed abelisaurids, although most noasaurids had much more traditional body types generally similar to other theropods. Their heads, on the other hand, had unusual adaptations depending on the subfamily. 'Traditional' noasaurids, sometimes grouped in the subfamily Noasaurinae, had sharp teeth which splayed outwards from a downturned lower jaw.

Jiangjunosaurus is a genus of herbivorous stegosaurian dinosaur from the Oxfordian-age Shishugou Formation of the Junggar Basin, Xinjiang, China.

<i>Miragaia longicollum</i> Extinct species of dinosaur

Miragaia is a long-necked stegosaurid dinosaur. Its fossils have been found in Upper Jurassic rocks in Portugal and possibly also Wyoming, United States. Miragaia has the longest neck known for any stegosaurian, which included at least seventeen vertebrae.

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

Leshansaurus is a genus of theropod dinosaur from the Late Jurassic Shaximiao Formation of what is now China. It was described in 2009 by a team of Chinese paleontologists. The type species is Leshansaurus qianweiensis. Fossils of Leshansaurus were discovered in strata from the Shangshaximiao Formation, a formation rich in dinosaur fossils. Li et al. referred this taxon to Sinraptoridae – a group of carnosaurian theropods, but it may it belong to Megalosauridae instead.

<i>Jesairosaurus</i> Extinct genus of reptiles

Jesairosaurus is an extinct genus of early archosauromorph reptile known from the Illizi Province of Algeria. It is known from a single species, Jesairosaurus lehmani. Although a potential relative of the long-necked tanystropheids, this lightly-built reptile could instead be characterized by its relatively short neck as well as various skull features.

<i>Ichthyovenator</i> Genus of dinosaur

Ichthyovenator is a genus of spinosaurid dinosaur that lived in what is now Laos, sometime between 125 and 113 million years ago, during the Aptian stage of the Early Cretaceous period. It is known from fossils collected from the Grès supérieurs Formation of the Savannakhet Basin, the first of which were found in 2010, consisting of a partial skeleton without the skull or limbs. This specimen became the holotype of the new genus and species Ichthyovenator laosensis, and was described by palaeontologist Ronan Allain and colleagues in 2012. The generic name, meaning "fish hunter", refers to its assumed piscivorous lifestyle, while the specific name alludes to the country of Laos. In 2014, it was announced that more remains from the dig site had been recovered; these fossils included teeth, more vertebrae (backbones) and a pubic bone from the same individual.

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

Panguraptor is a genus of coelophysid theropod dinosaur known from fossils discovered in Lower Jurassic rocks of southern China. The type and only known species is Panguraptor lufengensis. The generic name refers to the deity Pangu but also to the supercontinent Pangaea for which in a geological context the same characters are used: 盘古. Raptor means "seizer", "robber" in Latin. The specific name is a reference to the Lufeng Formation.The holotype specimen was recovered on 12 October 2007 from the Lufeng Formation of Yunnan, which is noted for sauropodomorph fossils. It was described in 2014 by You Hai-Lu and colleagues.

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

Dracoraptor is a genus of neotheropod dinosaur that lived during the Hettangian stage of the Early Jurassic Period of what is now Wales, sometime between 201 to 199 million years ago. It was discovered in 2014 at the Blue Lias Formation of the United Kingdom, and named in 2016 by British palaeontologist David Martill and colleagues, with the type species being Dracoraptor hanigani.

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

Halszkaraptor is a genus of waterfowl-like dromaeosaurid dinosaurs from Mongolia that lived during the Late Cretaceous period. It contains only one known species, Halszkaraptor escuilliei.

<i>Caihong</i> Extinct genus of birds

Caihong is a genus of small paravian theropod dinosaur from China that lived during the Late Jurassic period.

<i>Asfaltovenator</i> Extinct genus of reptiles

Asfaltovenator is a genus of basal tetanuran, possibly allosauroid dinosaur from the Middle Jurassic Cañadón Asfalto Formation from Chubut Province, Argentina. The type and only species is Asfaltovenator vialidadi. The names of this genus and species are nomina nuda due to their description not being published physically and lacking a ZooBank registration.

References

  1. 1 2 3 4 He Xinlu (1984). "The vertebrate fossils of Sichuan." Sichuan Scientific and Technological Publishing House, Chengdu. 40: 1-168
  2. Carrano, M.T.; Benson, R.B.J.; & Sampson, S.D., 2012, "The phylogeny of Tetanurae (Dinosauria: Theropoda)", Journal of Systematic Palaeontology 10(2): 211–300
  3. Holtz, Thomas R. Jr. (2012) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2011 Appendix.