Shanag

Last updated

Shanag
Temporal range: Early Cretaceous, 130  Ma
O
S
D
C
P
T
J
K
Pg
N
Shanag skull.png
Reconstructed Skull
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Paraves
Family: Dromaeosauridae
Genus: Shanag
Turner et al., 2007
Species:
S. ashile
Binomial name
Shanag ashile
Turner et al., 2007

Shanag is a genus of dromaeosaurid theropod dinosaur from the Early Cretaceous Period of Mongolia.

Contents

The type species of Shanag is S. ashile. It was named and described by Alan Turner, Sunny Hai-Ching Hwang and Mark Norell in 2007. The generic name refers to the black-hatted dancers in the Buddhist Cham dance. The specific name refers to the Ashile Formation, the old name for the layers where Shanag was found, used by Henry Fairfield Osborn. [1]

The holotype of Shanag, IGM 100/1119, was discovered in the Öösh Formation, the stratification of which is uncertain but probably dating to the Berriasian-Barremian. Shanag bears a strong resemblance to basal Chinese dromaeosaurids such as Microraptor and Sinornithosaurus , suggesting a close similarity between the fauna of the Öösh deposits, dated tentatively to 130 million years ago, and the Jehol Biota of China (such as the animals found in the roughly contemporary Yixian Formation), during the Early Cretaceous. [1]

Shanag was a small predator. In 2010 Gregory S. Paul estimated its length at 1.5 meters, the weight at five kilograms. [2] Shanag shows a mixture of dromaeosaurid, troodontid and basal avialan traits. [1]

Turner et al. assigned Shanag to the Dromaeosauridae. Their cladistic analysis indicated that it was a basal dromaeosaurid but higher in the tree than the Unenlagiinae. [1] Later analyses recovered it in the Microraptorinae. [3]

Morphology

The holotype specimen, about six centimeters long, is composed of an associated uncompressed upper and lower jaw fragment, containing a nearly complete right maxilla with teeth, a partial right dentary with teeth and an attached partial splenial. [1] The fossilized teeth in the specimen were pointed with serrations along the lengths of the posterior teeth, but no anterior teeth were available. [1] Shanag is autopomorphic as it lacks promaxillary fenestra and has interalveolar pneumatic cavities, which separates it from its nearest relative of S. millenii. [1] Its teeth have unusually long root lengths, making up about 70% of the overall tooth length. [1]

As part of the Theropoda group, Shanag had hollow bones and feathers. Though most were not capable of flight, some theropods used their feathers to assist in climbing or simply scrambling up tree trunks. [4] Feathers also allowed for thermoregulation by reducing the amount of airflow near the skin and preventing heat loss. [5] Their wings, though not capable of flight, could be used to stabilize themselves while on their prey via flapping like extant raptor birds. [6] Shanag are also believed to be endothermic based on their high speed and high level of activity. [4]

Family dromaeosaurida’s sharp middle toe (D-II) claws were initially thought to be for disemboweling prey, and then later tests suggested that due to the claw’s strength and cutting ability that they were used as a climbing tool for scaling the backs of prey larger than themselves. [7] This claim of scaling was later contested, and it was suggested the claws were used to grip and pin down prey similarly to extant birds of prey. [6]

Artist's reconstruction of Shanag ashile. Shanag.jpg
Artist's reconstruction of Shanag ashile.

See also

Related Research Articles

<i>Velociraptor</i> Dromaeosaurid dinosaur genus from the Late Cretaceous

Velociraptor is a genus of small dromaeosaurid dinosaurs that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis, named and described in 1924. Fossils of this species have been discovered in the Djadochta Formation, Mongolia. A second species, V. osmolskae, was named in 2008 for skull material from the Bayan Mandahu Formation, China.

<i>Deinonychus</i> Genus of theropod dinosaur

Deinonychus is a genus of dromaeosaurid theropod dinosaur with one described species, Deinonychus antirrhopus. This species, which could grow up to 3.4 meters (11 ft) long, lived during the early Cretaceous Period, about 115–108 million years ago. Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland.

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

Troodontidae is a clade of bird-like theropod dinosaurs. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens, have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like Sinovenator, demonstrate striking anatomical similarities with Archaeopteryx and primitive dromaeosaurids, and demonstrate that they are relatives comprising a clade called Paraves.

<i>Utahraptor</i> Genus of dinosaur from the Early Cretaceous

Utahraptor is a genus of large dromaeosaurid dinosaur that lived during the Early Cretaceous period from around 135 to 130 million years ago in what is now the United States. The genus was described in 1993 by an American paleontologist James Kirkland and colleagues with the type species Utahraptor ostrommaysi, based on fossils that had been unearthed earlier from the Cedar Mountain Formation of Utah. Later, many additional specimens were described including those from the skull and postcranium in addition to those of younger individuals.

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

Deinonychosauria is a clade of paravian dinosaurs which lived from the Late Jurassic to the Late Cretaceous periods. Fossils have been found across the globe in North America, Europe, Africa, Asia, South America, and Antarctica, with fossilized teeth giving credence to the possibility that they inhabited Australia as well. This group of dinosaurs are known for their sickle-shaped toe claws and features in the shoulder bones.

<span class="mw-page-title-main">Dromaeosauridae</span> Family of theropod dinosaurs

Dromaeosauridae is a family of feathered coelurosaurian theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek δρομαῖος (dromaîos), meaning 'running at full speed', 'swift', and σαῦρος (saûros), meaning 'lizard'. In informal usage, they are often called raptors, a term popularized by the film Jurassic Park; several genera include the term "raptor" directly in their name, and popular culture has come to emphasize their bird-like appearance and speculated bird-like behavior.

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

Microraptor is a genus of small, four-winged dromaeosaurid dinosaurs. Numerous well-preserved fossil specimens have been recovered from Liaoning, China. They date from the early Cretaceous Jiufotang Formation, 125 to 120 million years ago. Three species have been named, though further study has suggested that all of them represent variation in a single species, which is properly called M. zhaoianus. Cryptovolans, initially described as another four-winged dinosaur, is usually considered to be a synonym of Microraptor.

<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>Saurornitholestes</i> Extinct genus of dinosaurs

Saurornitholestes is a genus of carnivorous dromaeosaurid theropod dinosaur from the late Cretaceous of Canada (Alberta) and the United States.

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

Adasaurus is a genus of dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous period about 70 million years ago. The genus is known from two partial specimens found in the Nemegt Formation of Mongolia that were partially described in 1983 by the paleontologist Rinchen Barsbold.

<i>Achillobator</i> Extinct dromaeosaurid genus from the Late Cretaceous

Achillobator is a genus of large dromaeosaurid theropod dinosaur that lived during the Late Cretaceous period about 96 million to 89 million years ago in what is now the Bayan Shireh Formation of Mongolia. The genus is currently monotypic, only including the type species A. giganticus. The first remains were found in 1989 during a Mongolian-Russian field expedition and later described in 1999. Remains at the type locality of Achillobator may represent additional specimens. It represents the first and largest dromaeosaurid known from the Bayan Shireh Formation.

Unenlagia is a genus of dromaeosaurid theropod dinosaur that lived in South America during the Late Cretaceous period. The genus Unenlagia has been assigned two species: U. comahuensis, the type species described by Novas and Puerta in 1997, and U. paynemili, described by Calvo et al. in 2004.

<span class="mw-page-title-main">Velociraptorinae</span> Extinct subfamily of dinosaurs

Velociraptorinae is a subfamily of the theropod group Dromaeosauridae. The earliest velociraptorines are probably Nuthetes from the United Kingdom, and possibly Deinonychus from North America. However, several indeterminate velociraptorines have also been discovered, dating to the Kimmeridgian stage, in the Late Jurassic Period. These fossils were discovered in the Langenberg quarry, Oker near Goslar, Germany.

<span class="mw-page-title-main">Paraves</span> Clade of all dinosaurs that are more closely related to birds than to oviraptorosaurs

Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the avialans, which include diverse extinct taxa as well as the over 10,000 species of living birds. Basal members of Paraves are well known for the possession of an enlarged claw on the second digit of the foot, which was held off the ground when walking in some species. A number of differing scientific interpretations of the relationships between paravian taxa exist. New fossil discoveries and analyses make the classification of Paraves an active subject of research.

<i>Austroraptor</i> Genus of theropod dinosaurs

Austroraptor is a genus of dromaeosaurid theropod dinosaur that lived during the Campanian and Maastrichtian ages of the Late Cretaceous period in what is now Argentina.

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

Linheraptor is a genus of dromaeosaurid dinosaur which lived in what is now China in the Late Cretaceous. It was named by Xu Xing and colleagues in 2010, and contains the species Linheraptor exquisitus. This bird-like dinosaur was less than 2 m (6.5 ft) long and was found in Inner Mongolia. It is known from a single, nearly complete skeleton.

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

Eudromaeosauria is a subgroup of terrestrial dromaeosaurid theropod dinosaurs. They were small to large-sized, feathered hypercarnivores that flourished in the Cretaceous Period.

<i>Balaur bondoc</i> Extinct specie of dinosaurs

Balaur is a genus of theropod dinosaur from the late Cretaceous period, in what is now Romania. It is the type species of the monotypic genus Balaur, after the balaur, a dragon of Romanian folklore. The specific name bondoc means "stocky", so Balaur bondoc means "stocky dragon" in Romanian. This name refers to the greater musculature that Balaur had compared to its relatives. The genus, which was first described by scientists in August 2010, is known from two partial skeletons.

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

This timeline of dromaeosaurid research is a chronological listing of events in the history of paleontology focused on the dromaeosaurids, a group of sickle-clawed, bird-like theropod dinosaurs including animals like Velociraptor. Since the Native Americans of Montana used the sediments of the Cloverly Formation to produce pigments, they may have encountered remains of the dromaeosaurid Deinonychus hundreds of years before these fossils came to the attention of formally trained scientists.

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

Dakotaraptor is a potentially chimaeric genus of large dromaeosaurid theropod dinosaur that lived in western North America during the Late Cretaceous period. The remains have been found in the Maastrichtian-aged Hell Creek Formation, dated to the very end of the Mesozoic era, making Dakotaraptor one of the last surviving dromaeosaurids. The remains of D. steini were discovered in a multi-species bonebed. Elements of the holotype and referred specimens were later found to belong to trionychid turtles and further analysis of potential non-dromaeosaurid affinities of the holotype and referred material have not yet been conducted. Phylogenetic analyses of D. steini place it in a variety of positions within Dromaeosauridae.

References

  1. 1 2 3 4 5 6 7 8 Turner, A.S.; Hwang, S.H.; Norell, M.A. (2007). "A small derived theropod from Öösh, Early Cretaceous, Baykhangor Mongolia" (PDF). American Museum Novitates (3557): 1–27. doi:10.1206/0003-0082(2007)3557[1:ASDTFS]2.0.CO;2 . Retrieved 2007-03-29.
  2. Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 133
  3. Longrich, N.R.; Currie, P.J. (2009). "A microraptorine (Dinosauria–Dromaeosauridae) from the Late Cretaceous of North America". PNAS. 106 (13): 5002–7. Bibcode:2009PNAS..106.5002L. doi: 10.1073/pnas.0811664106 . PMC   2664043 . PMID   19289829.
  4. 1 2 Sattler, Helen Roney; et al. (et. al) (1983). The Illustrated Dinosaur Dictionary. Illustrated by Pamela Carroll et al. Lothrop, Lee & Shepard Books.
  5. Schwab, R.; V., Schafer (1972). "Avian Thermoregulation and Its Significance in Starling Control". Vetebr Pest Conf Proc: 127–37.
  6. 1 2 Fowler, Denver W.; Freedman, Elizabeth A.; Scannella, John B.; Kambic, Robert E. (2011-12-14). Farke, Andrew Allen (ed.). "The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds". PLOS ONE. 6 (12): e28964. doi: 10.1371/journal.pone.0028964 . ISSN   1932-6203. PMC   3237572 . PMID   22194962.
  7. Long, John A. (2008). Feathered dinosaurs : the origin of birds . Peter Schouten. Oxford: Oxford University Press. ISBN   978-0-19-537266-3. OCLC   190843466.