Santanaraptor

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Santanaraptor
Temporal range: Aptian-Albian, 112  Ma
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Esqueleto de Santanaraptor MN 01.jpg
Reconstructed skeleton
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Pantyrannosauria
Genus: Santanaraptor
Kellner, 1999
Type species
Santanaraptor placidus
Kellner, 1999

Santanaraptor (meaning "Santana Formation thief") is a genus of tyrannosauroid theropod dinosaur that lived in South America during the Early Cretaceous (late Aptian-early Albian), about 112 million years ago.

Contents

Discovery

The type species is S. placidus, first described by Kellner in 1999. [1] The species epithet refers to Placido Cidade Nuvens  [ pt ], who founded the Museu de Paleontologia da Universidade Regional do Cariri.

Description

Size comparison Santanaraptor placidus size chart.png
Size comparison

The holotype (MN 4802-V) is a juvenile partial skeleton consisting of three caudal vertebrae with chevrons, ischia, femora, tibia, fibula, pes, and soft tissue. The fossilized tissue includes a thin epidermis, [2] muscle fibers, and possibly blood vessels. [3] Skin impressions under the left foot are also preserved, showing scales. [2] It was unearthed in 1996 from the Romualdo Formation (Santana Group) in the Ceará State, northeastern Brazil. [4] While primarily known from hindquarter elements, the individual represented by the fossil may have reached 1.5 metres (4.9 ft) in length and 15 kilograms (33 lb) in mass. [5] The fossil consists of bones from the pelvis, hindlimbs, and tail. These provide little information on its overall appearance. However, it was definitely a coelurosaur, and a few of its details suggest that it might be a member of the tyrannosauroids. It is presumed to be similar to Dilong and Guanlong in that it had long arms, three fingered hands, and slim hindlimbs. [4]

Classification

Hypothetical life restoration Santanaraptor placidus.jpg
Hypothetical life restoration

Santanaraptor was originally thought to be a maniraptoran theropod when it was first discovered. However, it is now thought to be a basal coelurosaur based on several features present on the femur. Santanaraptor was tabulated by Holtz (2004) as the first tyrannosauroid known from Gondwana, [6] a position also found by Delcourt and Grillo (2018). [7] However, this position has been criticised, as the supposed tyrannosauroid characters are widely distributed in Coelurosauria, and several aspects of the foot are more similar to noasaurids. [8]

See also

Related Research Articles

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<span class="mw-page-title-main">Coelurosauria</span> Clade of dinosaurs

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<span class="mw-page-title-main">Romualdo Formation</span> Brazilian geologic formation

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<i>Fukuiraptor</i> Megaraptoran theropod dinosaur genus from the Early Cretaceous epoch

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

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

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

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

Timimus is a genus of small coelurosaurian theropod dinosaur from the Early Cretaceous of Australia. It was originally identified as an ornithomimosaur, but now it is thought to be a different kind of theropod, possibly a tyrannosauroid.

<span class="mw-page-title-main">Tyrannosauroidea</span> Extinct superfamily of dinosaurs

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

Compsognathidae is a family of coelurosaurian theropod dinosaurs. Compsognathids were small carnivores, generally conservative in form, hailing from the Jurassic and Cretaceous Periods. The bird-like features of these species, along with other dinosaurs such as Archaeopteryx inspired the idea for the connection between dinosaur reptiles and modern-day avian species. Compsognathid fossils preserve diverse integument — skin impressions are known from four genera commonly placed in the group, Compsognathus, Sinosauropteryx, Sinocalliopteryx, and Juravenator. While the latter three show evidence of a covering of some of the earliest primitive feathers over much of the body, Juravenator and Compsognathus also show evidence of scales on the tail or hind legs. "Ubirajara jubatus", informally described in 2020, had elaborate integumentary structures on its back and shoulders superficially similar to the display feathers of a standardwing bird-of-paradise, and unlike any other non-avian dinosaur currently described.

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

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

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

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

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<i>Sciurumimus</i> Extinct species of reptile

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<span class="mw-page-title-main">Timeline of tyrannosaur research</span>

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References

  1. Kellner, A. W. A. (1999). "Short Note on a new dinosaur (Theropoda, Coelurosauria) from the Santana Formation (Romualdo Member, Albian), northeastern Brazil". Boletim do Museu Nacional (Serie Geologia). 49: 1–8.
  2. 1 2 Hendrickx, Christophe; Bell, Phil R.; Pittman, Michael; Milner, Andrew R. C.; Cuesta, Elena; O'Connor, Jingmai; Loewen, Mark; Currie, Philip J.; Mateus, Octávio; Kaye, Thomas G.; Delcourt, Rafael (2022). "Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs". Biological Reviews. 97 (3): 960–1004. doi:10.1111/brv.12829. ISSN   1469-185X. PMID   34991180. S2CID   245820672.
  3. Kellner, A. W. A. (1996). Fossilized theropod soft tissue. Nature379, 32. doi: https://doi.org/10.1038/379032a0
  4. 1 2 Benton, Michael J. (2012). Prehistoric Life. Edinburgh, Scotland: Dorling Kindersley. p. 321. ISBN   978-0-7566-9910-9.
  5. Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs (2nd ed.). New Jersey: Princeton University Press. p. 108. ISBN   978-0691167664.
  6. Holtz, Thomas R. Jr. (2004). "Tyrannosauroidea". The Dinosauria (Second ed.). University of California Press.
  7. Delcourt, Rafael; Grillo, Orlando Nelson (2018). "Tyrannosauroids from the Southern Hemisphere: Implications for biogeography, evolution, and taxonomy". Palaeogeography, Palaeoclimatology, Palaeoecology. 511: 379–387. Bibcode:2018PPP...511..379D. doi:10.1016/j.palaeo.2018.09.003. S2CID   133830150.
  8. Doran Brownstein, Chase (2021). "Dinosaurs from the Santonian–Campanian Atlantic coastline substantiate phylogenetic signatures of vicariance in Cretaceous North America". Royal Society Open Science. 8 (8): 210127. Bibcode:2021RSOS....810127D. doi:10.1098/rsos.210127. PMC   8385347 . PMID   34457333.