User:A Cynical Idealist/sandbox5
| A Cynical Idealist/sandbox5 Temporal range: Early Cretaceous
~126 Ma - Late | |
|---|---|
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| The holotype on display in the Geological Museum of China | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Clade: | †Ornithomimosauria |
| Clade: | †Macrocheiriformes |
| Genus: | †Shenzhousaurus Ji et al., 2003 |
| Type species | |
| †Shenzhousaurus orientalis Ji et al., 2003
| |
Shenzhousaurus (/ˌʃenˈd͡ʒouˈsɔːrəs/; meaning "lizard from the Divine Land", after an ancient name for China) is an extinct genus of ornithomimosaurian theropod dinosaur that was discovered in the Early Cretaceous Yixian Formation of Liaoning, China. The genus contains a single species, the type species S. orientalis, named after the Latin word for "eastern". There is only one specimen of the genus, which preserves most of the body, the head, the tail, one hand, and parts of the legs.[1]
Discovery
[edit]
Shenzhousaurus was discovered by Chinese farmers at a locality called Sihetun, which is near Beipiao in western Liaoning Province in China. It was the first ornithomimosaur to be recovered from the Yixian Formation. When the specimen was excavated, it was accidentally broken, and the block containing the skeleton was split in half. This destroyed several of the bones, including those of the head, which are crushed.[1]
During preparation, the two blocks were rejoined and then the matrix surrounding the specimen was removed. The skeleton is relatively complete, however most of the forelimbs are missing along with the pectoral girdle and the very end of the tail. The parts of the specimen which are preserved are fully articulated, and the skeleton is positioned in the theropod death pose.[1]
Shenzhousaurus was formally described in 2003 in the American Museum Novitates (the in-house publication for the American Museum of Natural History) by Qiang Ji, Mark Norell, Peter Makovicky, Ke-Qin Gao, Shu'An Ji, Chongxi Yuan. It was notable among ornithomimosaurs at the time because of the presence of teeth in the jaws, when most ornithomimosaurs known from the time were edentulous.[1]
The holotype, and only specimen, of Shenzhousaurus was given the designation NGMC 97-4-002 and is on display in the Geological Museum of China in Beijing.[1]
Description
[edit]
Shenzhousaurus was a relatively small ornithomimosaur comparable in size to other small coelurosaurs like Caudipteryx, Sinornithosaurus, and Huaxiagnathus. The authors of its description found that the skull of the holotype was 185 millimetres (7.3 in) long, the femur was 191 millimetres (7.5 in), and the preserved elements of the vertebral column (7th pre-sacral to the 14th caudal) was 658 millimetres (2.159 ft) in length. However, due to the incompleteness of the skeleton, Ji and colleagues did not provide an estimate of the animal's full size.[1] Gregory S. Paul estimated that the adult size of Shenzhousaurus was around 1.6 metres (5.2 ft) long and 10 kilograms (22 lb).[2] Rubén Molina-Pérez and Asier Larramendi gave a roughly similar estimate of 1.7 metres (5.6 ft) long and 12 kilograms (26 lb)[3]
The holotype of Shenzhousaurus consists of a partial skull, a left mandible, six teeth, seven dorsal vertebrae, a complete pelvis including the sacrum, a femur, fourteen caudal vertebrae and associated chevrons, one metacarpal, five phalanges from the hands, and four manual unguals. From the parts preserved, Ji and colleagues were able to distinguish Shenzhousaurus from all other ornithomimosaurs by the following combination of traits: the posterior half of the dentary is edentulous, the ischium is straight rather than curved, the post-acetabular process is curved and non-truncated, and the first digit of the hand is shorter than the other two digits. Several of these traits are not truly autapomorphic and are present in the related genera Harpymimus and Pelecanimimus. However, the combination of these primitive features in Shenzhousaurus appears to be novel. Both the skull not the postcranial skeleton have yet to receive a comprehensive osteology, with the only published information on the specimen being found in the preliminary description.[1]
Skull
[edit]
The holotype skull of Shenzhousaurus was significantly deformed post-mortem, and some of the skull is still obscured by the rock matrix from which it has not fully been removed. Most of the known skull elements are from the left side of the head, which is fully exposed from the rock. The bones preserved in the skull include the left premaxilla, maxilla, pterygoid, lacrimal, dentary, surangular, angular, jugal, squamosal, both nasals, both parietals, part of the right postorbital, parts of both palatines, parts of the left ectopterygoid, and the right frontal. Several severely deformed bones in the posterior portion of the skull have also been tentatively identified as the laterosphenoid and prootic, both making up part of the braincase.[1]
The skull is elongated, and much of the elongation occurs along the length of the maxillae and nasals, because the premaxillae are very short. The elongation of the maxillae is accompanied by an elongation of the antorbital fenestra and the appearance of an accessory fenestra in the anterior portion of the antorbital fossa. The portion of the maxilla anterior to the antorbital fenestra — about 40% of its total length — is relatively flat except for the presence of neurovascular foramina.[1]
The articulations between the maxillae, jugals, lacrimals, and frontals are unclear due to deformation of the fossil, but it is clear that Shenzhousaurus did not possess any lacrimal display structures (as is seen in Allosaurus, Yangchuanosaurus, tyrannosaurids, etc.). The right postorbital is relatively massive, which differs from the condition seen in Ornithomimidae. It also differs from the maniraptoran condition in which the postorbital is curved anterodorsally.[1]
The bones from the dorsal portion of the neurocranium are more damaged than the anterior bones of the facial skeleton. The parietals appear to be paired, rather than fused, and there is no sagittal crest along the dorsal margin of the parietals. The squamosals are preserved disarticulated, but it is known to be tetraradiate (having four extending processes) in shape and possessed a relatively sharp edge along the dorsal margin of the superior temporal fenestra, similar to the condition seen in Gallimimus. The portion of the squamosal which articulates with the quadrate is triangular in shape and would have been obscured by the quadrate in lateral view.[1]
Parts of the palate of Shenzhousaurus are visible in the holotype because the large fenestrations of the maxilla prevent these bones from being more obscured by the facial skeleton. The palatines possess an interchoanal bar that is relatively slender and curves posteriorly, similar to the condition seen in eudromaeosaurs, and the pterygoid process of the palatines extend anterior to the lacrimals, although the pterygoids themselves are not visible in the fossil. The hooked jugal process of the ectopterygoid is the only part of this bone that is visible and it meets the jugal posterior to the pterygoid process of the palatine. There are also several disarticulated and crushed portions of bone visible through the antorbital fenestra, which the authors hypothesized are the left pterygoid and part of the laterosphenoid, although this is uncertain.[1]
The entirety of the left mandible is preserved, but a disarticulated portion of the braincase obscures part of the posterior bones, meaning the posterior-most portion of the mandible is not visible. The lateral surface of the dentary bears three rows of neurovascular foramina which extend along the anterior part of the bone, below the teeth. The foramina are absent in the posterior half of the dentary, which also lacks teeth. The external mandibular fenestra is reduced in size, which is a condition shared by other ornithomimosaurs. Small parts of the angular and surangular are also visible, and despite being crushed, the retroarticular process is visible and appears to expand medially. The dentary only preserves seven teeth, but there were likely at least nine teeth in the lower jaw. The teeth themselves are peg-like and possess no carinae or serrations. The number of teeth present in the maxilla and premaxilla in life is unknown because the alveoli are obscured by the matrix.[1]
Postcranial skeleton
[edit]- Dorsals and ribs
- Sacrals
- Caudals and chevrons
- Pelvis
- Arms
- Legs
The holotype of Shenzhousaurus preserves almost the entire vertebral series. It notably lacks the cervical vertebrae as well as a few of the posterior caudal vertebrae.
Ichnofossils
[edit]Classification
[edit]
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_(Antwerpener_Breiftaube).jpg){kind=small}
Similar or identical results to Lee and colleagues were found in a prior analysis of ornithomimosuar phylogeny by Xu and colleagues in 2011, although this analysis did not include data on Deinocheirus.[8] Subsequent analyses have also recovered this result including those of Brusatte and colleagues in 2014,[9] Hattori and colleagues in 2023,[10] and Samathi in 2024.[11]
| Maniraptoriformes |
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Paleobiology
[edit]Integument
[edit]
Pneumaticity
[edit]
- Pneumaticity[14]
Locomotion
[edit]
- Footprints[15]
Paleoecology
[edit]Diet
[edit]Predators
[edit].png)
Paleoenvironment
[edit]
Contemporary fauna
[edit]
Lujiatun Bed
- Herbivores: cf. Euhelopus, Liaoceratops, Psittacosaurus, Changmiania, Jeholosaurus
- Maniraptorans: Liaoningornis, Graciliraptor, Incisivosaurus, Daliansaurus, Mei, Sinovenator, Sinusonasus
- Pterosaurs: Moganopterus
- Mammals: Acristatherium, Gobiconodon, Juchilestes, Maotherium, Meemannodon, Repenomamus
See also
[edit]- Feathered dinosaurs
- Institute of Vertebrate Paleontology and Paleoanthropology
- List of non-avian dinosaur species preserved with evidence of feathers
- Timeline of ornithomimosaur research
Source gathering
[edit]- Hexing[24]
Gallery
[edit]-
Psittacosaurus bonebed -
Psittacosaurus and turtle -
Hyphalosaurus -
Specimen with quill knobs
_NMNS.jpg)
References
[edit]- ^ a b c d e f g h i j k l m Ji, Qiang; Norell, Mark A.; Makovicky, Peter J.; Gao, KE-QIN; Ji, SHU'AN; Yuan, Chongxi (2003). "An Early Ostrich Dinosaur and Implications for Ornithomimosaur Phylogeny". American Museum Novitates (3420): 1. doi:10.1206/0003-0082(2003)420<0001:AEODAI>2.0.CO;2. ISSN 0003-0082.
- ^ Paul, Gregory S. (2024). The Princeton Field Guide to Dinosaurs (Third Edition). Princeton, New Jersey: Princeton University Press. ISBN 978-0691231570.
- ^ Molina-Pérez, Rubén; Larramendi, Asier (2019). Dinosaur Facts and Figures: The Theropods and Other Dinosauriformes. Translated by Connolly, David; Ramírez Cruz, Gonzalo Ángel. Illustrated by Andrey Atuchin and Sante Mazzei. Princeton University Press. ISBN 978-0691180311.
- ^ Lee, Y.N.; Barsbold, R.; Currie, P.J.; Kobayashi, Y.; Lee, H.J.; Godefroit, P.; Escuillié, F.O.; Chinzorig, T. (2014). "Resolving the long-standing enigmas of a giant ornithomimosaur Deinocheirus mirificus". Nature. 515 (7526): 257–260. Bibcode:2014Natur.515..257L. doi:10.1038/nature13874. PMID 25337880. S2CID 2986017.
- ^ Cau A. (2024). A Unified Framework for Predatory Dinosaur Macroevolution. Bollettino della Società Paleontologica Italiana, 63(1): 1-19.
- ^ Cuesta E, Vidal D, Ortega F, Shibata M, Sanz JL (2021). "Pelecanimimus (Theropoda: Ornithomimosauria) postcranial anatomy and the evolution of the specialized manus in Ornithomimosaurs and sternum in maniraptoriforms". Zoological Journal of the Linnean Society. 194 (2): 553–591. doi:10.1093/zoolinnean/zlab013.
- ^ Sereno, P. (2017). "Early Cretaceous ornithomimosaurs (Dinosauria: Coelurosauria) from Africa". Ameghiniana. 54 (5): 576–616. doi:10.5710/AMGH.23.10.2017.3155. S2CID 134718338.
- ^ Li Xu; Yoshitsugu Kobayashi; Junchang Lü; Yuong-Nam Lee; Yongqing Liu; Kohei Tanaka; Xingliao Zhang; Songhai Jia; Jiming Zhang (2011). "A new ornithomimid dinosaur with North American affinities from the Late Cretaceous Qiupa Formation in Henan Province of China". Cretaceous Research. 32 (2): 213–222. doi:10.1016/j.cretres.2010.12.004.
- ^ Brusatte, Stephen L.; Lloyd, Graeme T.; Wang, Steve C.; Norell, Mark A. (2014). "Gradual Assembly of Avian Body Plan Culminated in Rapid Rates of Evolution across the Dinosaur-Bird Transition" (PDF). Current Biology. 24 (20): 2386–2392. doi:10.1016/j.cub.2014.08.034. PMID 25264248. S2CID 8879023.
- ^ Hattori, S.; Shibata, M.; Kawabe, S.; Imai, T.; Nishi, H.; Azuma, Y. (2023). "New theropod dinosaur from the Lower Cretaceous of Japan provides critical implications for the early evolution of ornithomimosaurs". Scientific Reports. 13. 13842. doi:10.1038/s41598-023-40804-3. PMC 10484975.
- ^ Samathi, Adun (2024). "Phylogenetic position of Kinnareemimus khonkaenensis (Dinosauria: Theropoda: Ornithomimosauria) from the Lower Cretaceous of Thailand". Zootaxa. 5448: 67–84. doi:10.11646/zootaxa.5448.1.4.
- ^ Van Der Reest, Aaron J.; Wolfe, Alexander P.; Currie, Philip J. (2016). "A densely feathered ornithomimid (Dinosauria: Theropoda) from the Upper Cretaceous Dinosaur Park Formation, Alberta, Canada". Cretaceous Research. 58: 108–117. doi:10.1016/j.cretres.2015.10.004.
- ^ Darla K. Zelenitsky; François Therrien; Gregory M. Erickson; Christopher L. DeBuhr; Yoshitsugu Kobayashi; David A. Eberth; Frank Hadfield (2012). "Feathered Non-Avian Dinosaurs from North America Provide Insight into Wing Origins". Science. 338 (6106): 510–514. Bibcode:2012Sci...338..510Z. doi:10.1126/science.1225376. PMID 23112330. S2CID 2057698.
- ^ Watanabe, Akinobu; Eugenia Leone Gold, Maria; Brusatte, Stephen L.; Benson, Roger B. J.; Choiniere, Jonah; Davidson, Amy; Norell, Mark A. (2015). "Vertebral Pneumaticity in the Ornithomimosaur Archaeornithomimus (Dinosauria: Theropoda) Revealed by Computed Tomography Imaging and Reappraisal of Axial Pneumaticity in Ornithomimosauria". PLOS ONE. 10 (12): e0145168. Bibcode:2015PLoSO..1045168W. doi:10.1371/journal.pone.0145168. PMC 4684312. PMID 26682888.
- ^ Xing, Li-da; Harris, Jerald D.; Feng, Xiang-yang; Zhang, Zhi-jun (2009). "Theropod (Dinosauria: Saurischia) tracks from Lower Cretaceous Yixian Formation at Sihetun Village, Liaoning Province, China and possible track makers". Geological Bulletin of China. 28 (6): 705–712.
- ^ Cerda, Ignacio A. (2008). "Gastroliths in an Ornithopod Dinosaur". Acta Palaeontologica Polonica. 53 (2): 351–355. doi:10.4202/app.2008.0213.
- ^ Zanno, Lindsay E.; Makovicky, Peter J. (2011). "Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution". Proceedings of the National Academy of Sciences. 108 (1): 232–237. Bibcode:2011PNAS..108..232Z. doi:10.1073/pnas.1011924108. PMC 3017133. PMID 21173263.
- ^ Zhong, Yuting; Huyskens, Magdalena H; Yin, Qing-Zhu; Wang, Yaqiong; Ma, Qiang; Xu, Yi-Gang (2021-04-12). "High-precision geochronological constraints on the duration of 'Dinosaur Pompeii' and the Yixian Formation". National Science Review. 8 (6): nwab063. doi:10.1093/nsr/nwab063. ISSN 2095-5138. PMC 8288181. PMID 34691675.
- ^ Xu, Xing; Wang, Xiao-Lin; Wu, Xiao-Chun (1999). "A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China". Nature. 401 (6750): 262–266. Bibcode:1999Natur.401..262X. doi:10.1038/45769.
- ^ L. Xing, P. R. Bell, P. J. Currie, M. Shibata, K. Tseng and Z. Dong. 2012. A sauropod rib with an embedded theropod tooth: direct evidence for feeding behaviour in the Jehol Group, China. Lethaia 45:500-506
- ^ Matsukawa, Masaki; Shibata, Kenichiro; Sato, Kenta; Xing, Xu; Lockley, Martin G. (2014). "The Early Cretaceous terrestrial ecosystems of the Jehol Biota based on food-web and energy-flow models". Biological Journal of the Linnean Society. 113 (3): 836–853. doi:10.1111/bij.12368.
- ^ Zhou, Zhonghe; Wang, Yuan (2010). "Vertebrate diversity of the Jehol Biota as compared with other lagerstätten". Science China Earth Sciences. 53 (12): 1894–1907. Bibcode:2010ScChD..53.1894Z. doi:10.1007/s11430-010-4094-9.
- ^ Han, Gang; Mallon, Jordan C.; Lussier, Aaron J.; Wu, Xiao-Chun; Mitchell, Robert; Li, Ling-Ji (2023). "An extraordinary fossil captures the struggle for existence during the Mesozoic". Scientific Reports. 13 (1): 11221. Bibcode:2023NatSR..1311221H. doi:10.1038/s41598-023-37545-8. PMC 10354204. PMID 37464026.
- ^ Jin Liyong, Chen Jun and Pascal Godefroit (2012). "A New Basal Ornithomimosaur (Dinosauria: Theropoda) from the Early Cretaceous Yixian Formation, Northeast China". In Godefroit, P. (ed.). Bernissart Dinosaurs and Early Cretaceous Terrestrial Ecosystems. Indiana University Press. pp. 467–487. Bibcode:2012bdec.book.....G.