Zhuchengtitan

Last updated

Zhuchengtitan
Temporal range: Campanian, 73.5  Ma
O
S
D
C
P
T
J
K
Pg
N
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Macronaria
Clade: Titanosauria
Clade: Lithostrotia
Family: Saltasauridae
Genus: Zhuchengtitan
Mo et al., 2017
Type species
Zhuchengtitan zangjiazhuangensis
Mo et al., 2017

Zhuchengtitan (meaning "Zhucheng titan") is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Shandong, China. It contains a single species, Z. zangjiazhuangensis, named by Mo Jinyou and colleagues in 2017 from a single humerus. Zhuchengtitan can be identified by the extreme width of the top end of its humerus, as well as the expansion of the deltopectoral crest on its humerus; both of these characteristics indicate that it was likely closely related to Opisthocoelicaudia . However, it differs from the latter by the flatter bottom articulating surface of its humerus. Zhuchengtitan lived in a floodplain environment alongside Shantungosaurus , Zhuchengtyrannus , and Sinoceratops .

Contents

Discovery and naming

Zhuchengtitan is known from a single humerus that was discovered in the Wangshi Group within the region of Zhucheng, Shandong, China. The primary fossil localities within this region are the Longgujian, Kugou, and Zangjiazhuang Quarries. In 2008, researchers from the Zhucheng Dinosaur Culture Research Center uncovered the humerus and some other sauropod bones at the Zangjiazhuang Quarry; the humerus was catalogued as ZJZ-57 at the center. While the humerus is mostly complete, the outer edge of the top end, all edges of the bottom end save for the rear edge, and the deltopectoral crest have all been partially lost to damage. Additionally, the preserved portions are twisted. [1]

Locally, the Wangshi Group is further divided into two smaller units, the Xingezhuang and Hongtuya Formations. Deposits in the Xingezhuang Formation consist of multi-colored clastic rocks formed from siltstone, sandstone, and grey-colored clay, while deposits in the Hongtuya Formation consist of red interfingering layers of sandstone and conglomerate, capped at the top by a basalt layer. The boundary between the two is formed by sandy conglomerate and sandstone deposits; [2] ZJZ-57 originates from this boundary. [1]

In 2017, ZJZ-57 was described by Mo Jinyou, Wang Kebai, Chen Shuqing, Wang Peiye, and Xu Xing in a research paper published in the Geological Bulletin of China. They named it as a new genus and species of titanosaurian sauropod Zhuchengtitan zangjiazhuangensis; the genus name Zhuchengtitan combines Zhucheng with the Greek suffix titan ("titan", for "titanosaur"), while zangjiazhuangensis refers to its origin from the Zangjiazhuang Quarry. [1]

Description

Reconstruction of the closely related Opisthocoelicaudia Opisthocoelicaudia.jpg
Reconstruction of the closely related Opisthocoelicaudia

The humerus ZJZ-57 (when viewed from the front) measures 108 centimetres (43 in) long, 59.3 centimetres (23.3 in) wide at the top, 23.1 centimetres (9.1 in) wide at midshaft, and 37.5 centimetres (14.8 in) wide at the bottom. It can be identified by the extreme width of its top end compared to other titanosaurs, which is 0.55 times its whole length. This figure is closest to the 0.49 of Saltasaurus [3] and the 0.56 of Opisthocoelicaudia . [4] Consequently, the robustness index (RI) (the ratio between the average of the three width measurements and the length) is also quite high, at 0.39; Saltasaurus has an RI of 0.35, while Opisthocoelicaudia has an RI of 0.38. The width arises from the inner edge of the bone, which is angled more sharply inwards at the top end of the bone than the bottom end. [1]

Further below, the shaft of the bone is cylindrical in cross-section, with the long axis oriented sideways. The deltopectoral crest, which is located on the front surface near the top end of the bone, is very prominent, and bears a hook-like process about 1/3 of the way down its length. It extends downwards to the midshaft of the bone, and sideways so that it occupies the outer 2/5 of the bone's width. In Opisthocoelicaudia, the crest is wider, occupying 1/2 of the bone's width. The humerus forms a wide depression on the portion of the shaft further inward than the crest. [1]

Near the top end on the back of the bone, there are two depressions bordering a central ridge, which extends upwards to support the rounded humeral head. On the bottom of the bone, the two condyles that articulate respectively with the radius and ulna are separated by a broad but shallow intercondylar groove, and there is a low but robust ridge on either side of the groove. These structures are more prominent in Saltasaurus and Opisthocoelicaudia. The condyles are expanded towards the front of the bone; viewed from the bottom, the surface of the condyles is very roughened. [1]

Classification

On account of the inward and downward expansion of the deltopectoral crest, the localized swelling of the bone surrounding the crest, and the presence of a projecting process 1/3 of the way down the length of the crest, Mo and colleagues assigned Zhuchengtitan to the Saltasauridae, given the status of these traits as defining characteristics of the group. [5] [6] Despite differences in the condyles, they recognized that the form and proportions of the humerus, including the RI, were most similar to Opisthocoelicaudia. Thus, they hypothesized that Opisthocoelicaudia and Zhuchengtitan may be closely related, but noted that this conclusion would need to be confirmed by the discovery of additional material. As for other Asian titanosaurs, Zhuchengtitan can be distinguished from Qingxiusaurus , Huabeisaurus , Borealosaurus , and Phuwiangosaurus by the greater width of the top end of its humerus as well as its better-developed deltopectoral crest. It cannot be compared with other genera that lack preserved humeri. [1]

Paleoecology

Shantungosaurus was a contemporary of Zhuchengtitan Shantungosaurus life.png
Shantungosaurus was a contemporary of Zhuchengtitan

The deposits from which Zhuchengtitan originated are characteristic of alluvial fans, braided rivers, and floodplains. Based on argon-argon dating of the basalt layer at its top end, the Hongtuya Member at Zangjiazhuang has been estimated at 73.5 Ma in age, which places it during the Campanian epoch of the Cretaceous period. [2] Other dinosaurs found at Zangjiazhuang include the hadrosaurid ornithopod Shantungosaurus giganteus (referred to by Mo and colleagues as "Huaxiasaurus maximus"), [7] [8] the tyrannosaurid theropod Zhuchengtyrannus magnus , [9] and the ceratopsid Sinoceratops zhuchengensis . [10] Dinosaur fossils at Zangjiazhuang generally only consist of a few specimens except for the thousands of Shantungosaurus specimens that are known, which likely represent the victims of a sudden mass mortality event. [1]

See also

Related Research Articles

Titanosauria Extinct clade of dinosaurs

Titanosaurs were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as Patagotitan—estimated at 37 m (121 ft) long with a weight of 69 tonnes —and the comparably-sized Argentinosaurus and Puertasaurus from the same region.

Nemegtosauridae Extinct family of dinosaurs

Nemegtosauridae is a family of titanosaurian sauropod dinosaurs based on their diplodocid-like skulls. Only three species are known: Nemegtosaurus, Quaesitosaurus and Tapuiasaurus, each from the Cretaceous.

<i>Antarctosaurus</i> Sauropod dinosaur genus from Late Cretaceous

Antarctosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The type species, Antarctosaurus wichmannianus, and a second species, Antarctosaurus giganteus, were described by prolific German paleontologist Friedrich von Huene in 1929. Three additional species of Antarctosaurus have been named since then but later studies have considered them dubious or unlikely to pertain to the genus.

<i>Shantungosaurus</i> Hadrosaurid ornithopod dinosaur genus from the Late Cretaceous period

Shantungosaurus is a genus of very large saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, Shantungosaurus giganteus. The stratigraphic interval of Shantungosaurus ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late Campanian in age. Shantungosaurus is so far the largest hadrosauroid taxon in the world: the greatest length of its femur is about 1.7 metres (5.6 ft), and the greatest length of its humerus is about 0.97 metres (3.2 ft).

<i>Argyrosaurus</i> Genus of herbivorous titanosaurian sauropod dinosaur

Argyrosaurus is a genus of titanosaurian sauropod dinosaur that lived about 70 million years ago, during the Late Cretaceous Period of what is now Argentina.

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

Ampelosaurus is a titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now France. Its type species is A. atacis, named by Le Loeuff in 1995. A possible unnamed species has given Ampelosaurus an age reaching to the latest Cretaceous, from about 70 to 66 million years ago.

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

Andesaurus is a genus of basal titanosaurian sauropod dinosaur which existed during the middle of the Cretaceous Period in South America. Like most sauropods, it would have had a small head on the end of a long neck and an equally long tail. Andesaurus was a very large animal, as were many others of its relatives, which included the largest animals ever to walk the Earth.

Borealosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of northern China. The type species is Borealosaurus wimani, which was named in 2004.

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

Neuquensaurus is a genus of saltasaurid sauropod dinosaur that lived in the Late Cretaceous, about 80 million years ago in Argentina and Uruguay in South America. Its fossils were recovered from outcrops of the Anacleto Formation around Cinco Saltos, near the Neuquén river from which its name is derived.

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

Lirainosaurus is a genus of titanosaur sauropod which lived in what is now Spain. The type species, Lirainosaurus astibiae, was described by Sanz, Powell, Le Loeuff, Martinez, and Pereda-Suberbiola in 1999.

Fusuisaurus is a genus of sauropod dinosaur from the Early Cretaceous of China. Fragmentary postcranial remains of this animal have been discovered in 2001 in the Napai Formation of Guangxi, China and consist of the left ilium, left pubis, anterior caudals, most of the dorsal ribs and distal end of the left femur. This sauropod has been described as a basal titanosauriform.

Saltasauridae Extinct family of dinosaurs

Saltasauridae is a family of armored herbivorous sauropods from the Upper Cretaceous. They are known from fossils found in South America, Asia, North America, and Europe. They are characterized by their vertebrae and feet, which are similar to those of Saltasaurus, the first of the group to be discovered and the source of the name. The last and largest of the group and only one found in North America, Alamosaurus, was thirty-four metres in length and one of the last sauropods to go extinct.

Wangshi Group

The Wangshi Group is a geological Group in Shandong, China whose strata date back to the Coniacian to Campanian stages of the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the group.

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

Diamantinasaurus is a genus of titanosaurian sauropod from Australia that lived during the early Late Cretaceous, about 94 million years ago. The type species of the genus is D. matildae, first described and named in 2009 by Scott Hocknull and colleagues based on fossil finds in the Winton Formation. Meaning "Diamantina lizard", the name is derived from the location of the nearby Diamantina River and the Greek word sauros, "lizard". The specific epithet is from the Australian song Waltzing Matilda, also the locality of the holotype and paratype. The known skeleton includes most of the forelimb, shoulder girdle, pelvis, hindlimb and ribs of the holotype, and one shoulder bone, a radius and some vertebrae of the paratype.

<i>Zhuchengtyrannus</i> Tyrannosaurid theropod dinosaur genus from Late Cretaceous period

Zhuchengtyrannus is a genus of tyrannosaurid theropod dinosaur known from the Campanian stage of the Late Cretaceous of Shandong Province, China. It belongs to the tyrannosaurinae subfamily, and contains a single species, Zhuchengtyrannus magnus.

<i>Paralititan</i> Genus of a titanosaurian sauropod dinosaur

Paralititan was a giant titanosaurian sauropod dinosaur genus discovered in coastal deposits in the Upper Cretaceous Bahariya Formation of Egypt. It lived between 99.6 and 93.5 million years ago.

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

Savannasaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Winton Formation of Queensland, Australia. It contains one species, Savannasaurus elliottorum, named in 2016 by Stephen Poropat and colleagues. The holotype and only known specimen, originally nicknamed "Wade", is the most complete specimen of an Australian sauropod, and is held at the Australian Age of Dinosaurs museum. Dinosaurs known from contemporary rocks include its close relative Diamantinasaurus and the theropod Australovenator; associated teeth suggest that Australovenator may have fed on the holotype specimen.

Triunfosaurus is a genus of somphospondylan sauropod dinosaur from the Early Cretaceous of Brazil. It contains a single species, T. leonardii, described by Carvalho et al. in 2017. As a genus, Triunfosaurus can be distinguished from all other titanosaurs by the unique proportions of its ischium. It was initially described as a basal titanosaur, making it the earliest basal titanosaur known; however, subsequent research questioned the identification of the taxon as a titanosaur, instead reassigning it to the Somphospondyli.

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

Anomalipes zhaoi is an extinct caenagnathid dinosaur discovered in China. It lived during the Campanian-aged Wangshi Group in China. It is the only species in the genus Anomalipes.

Sinankylosaurus is a genus of ankylosaurian dinosaur from the late Cretaceous Period of Shandong, China. The genus contains a single species, Sinankylosaurus zhuchengensis, known from a nearly complete right illium. The describers explained that the discovery of Sinankylosaurus further demonstrates the similarity between dinosaurs of eastern Asia and western North America.

References

  1. 1 2 3 4 5 6 7 8 Mo, J.; Wang, K.; Chen, S.; Wang, P.; Xu, X. (2017). "A new titanosaurian sauropod from the Late Cretaceous strata of Shandong Province". Geological Bulletin of China. 36 (9): 1501–1505.
  2. 1 2 L., Y.; Kuang, H.; Peng, N.; Ji, Shuan; Wang, X.; Chen, S.; Zhang, Y.; Xu, H. (2010). "魯東諸城地區晚白堊世恐龍集群埋藏地沉積相與埋藏學初步研究" [Sedimentary Facies and Taphonomy of Late Cretaceous Deaths of Dinosaur, Zhucheng, Eastern Shandong]. Geological Review. 56 (4): 457–468.
  3. Powell, J.E. (1992). "Osteología de Saltasaurus loricatus (Sauropoda – Titanosauridae) del Cretácico Superior del noroeste Argentino" [Osteology of Saltasaurus loricatus (Sauropoda-Titanosauridae) of the Upper Cretaceous of Northwest Argentina](PDF). In Sanz, J.; Buscalioni, A. (eds.). Los Dinosaurios y Su Entorno Biótico: Actas del Segundo Curso de Paleontología in Cuenca[The Dinosaurs and Their Biotic Environment: Proceedings of the Second Congress of Paleontology in Cuenca]. Cuenca: Institutio "Juan de Valdes". pp. 165–230.
  4. Borsuk-Białynicka, M.M. (1977). "A new camarasaurid sauropod Opisthocoelicaudia skarzynskii gen. n., sp. n. from the Upper Cretaceous of Mongolia" (PDF). Palaeontologia Polonica. 37 (5): 5–64.
  5. Wilson, J.A. (2002). "Sauropod dinosaur phylogeny: critique and cladistic analysis" (PDF). Zoological Journal of the Linnean Society. 136 (2): 215–275. doi: 10.1046/j.1096-3642.2002.00029.x .
  6. D'Emic, M.D. (2012). "The early evolution of titanosauriform sauropod dinosaurs". Zoological Journal of the Linnean Society. 166 (3): 624–671. doi: 10.1111/j.1096-3642.2012.00853.x .
  7. Hone, D.W.E.; Sullivan, C.; Zhao, Q.; Wang, K.; Xu, X. (2015). "Body Size Distribution in a Death Assemblage of a Colossal Hadrosaurid from the Upper Cretaceous of Zhucheng, Shandong Province, China" (PDF). In Eberth, D.A.; Evans, D.C. (eds.). Hadrosaurs. Bloomington: Indiana University Press. pp. 524–531. ISBN   9780253013859.
  8. Zhao, X.J.; Wang, K.B.; Li, D.J. (2011). "巨大華夏龍" [Huaxiaosaurus aighatens]. Geological Bulletin of China. 30 (11): 1671–1688.
  9. Hone, D.W.E.; Wang, K.; Sullivan, C.; Zhao, X.; Chen, S.; Li, D.; Ji, S.; Ji, Q.; Xu, X. (2011). "A new, large tyrannosaurine theropod from the Upper Cretaceous of China". Cretaceous Research. 32 (4): 495–503. doi:10.1016/j.cretres.2011.03.005.
  10. Xu, X.; Wang, K.; Zhao, X.; Li, D. (2010). "First ceratopsid dinosaur from China and its biogeographical implications". Chinese Science Bulletin. 55 (16): 1631–1635. doi:10.1007/s11434-009-3614-5. S2CID   128972108.