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| + | {{Taxobox|image = mono.jpg}}'''''Mononykus''''' ({{IPAc-en|m|ə|ˈ|n|ɒ|n|ɨ|k|ə|s}} {{respell|mə|NON|i-kəs}}, sometimes {{IPAc-en|ˌ|m|ɒ|n|ɵ|ˈ|n|aɪ|k|ə|s}} {{respell|MON|o|NY|kəs}}; meaning "one claw") was a [[theropod]] [[dinosaur]] from late [[Cretaceous]] [[Mongolia]] ([[Nemegt Formation]], about 70 million years ago) with long, skinny legs. It moved about on two legs, was likely very nimble and could run at high speeds, something that would have been useful in the open [[desert]] [[plain]]s where it lived. It had a small skull, and its teeth were small and pointed, suggesting that it ate insects and small animals, such as lizards and mammals. Its large eyes might have allowed ''Mononykus'' to hunt by night, when it was cooler and there would have been fewer predators about. ''Mononykus'' was originally named ''Mononychus'' in 1993, but later that year, it was renamed because the original name had already been used for a [[beetle]] named by [[Johann Schueppel]], a German [[entomologist]]. |
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| − | [[File:Mononykus_Olecranus.jpg|thumb|340px]] ''Mononykus olecranus'' (meaning one claw) was a genus of Alvarezsauridae dinosaur from late cretaceous Mongolia. Only about 1 metre long this nimble two legged diosaur lived in the open desert plains where it could use its high speed to escape from predators. Mononykus probably ate small mammals, lizards and insects. It's large eye sockets suggest that it had very good night vision which meant it could take advantage of the cooler air and the lack of day time predators. |
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| + | ==Description== |
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| − | Mononykus was renamed in 1994 after the name it had been given a year earlier had already been taken by a beetle. Known from just a single holotype specimin which lacks a tail Mononykus previously had more remains, but they were reclassified as shuvuuia. Like most other alvarezsaurs mononykus only has one claw on each arm the purpose of these specialist arms still remains a mystery. Although no traces of feathers have been found it is still highly likely that Mononykus had feathers and is usually portraied or reconstructed with a downy layer of feathers covering its body |
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| + | ''Mononykus'' was a small dinosaur, only {{convert|1|m|ft}} long. Other characteristics include fused [[wrist]] bones similar to those of birds, and a keeled breastbone. It differed from close relatives ''[[Shuvuuia]]'' and ''[[Parvicursor]]'' in several details of its skeleton, including a pubic bone that is triangular in cross section, and different proportions in the toe bones. |
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| + | ''Mononykus'' is currently represented by a single [[holotype]] specimen, catalog number IGM N107/6. This specimen consists of a partial skeleton lacking a tail, and only small fragments of skull bones, including a complete braincase. Several other specimens were later misclassified as ''Mononykus'', including specimens with partial tails (initially misinterpreted as being very short, though later specimens showed they were long and thin) and complete skulls showing a distinct, mostly toothless form.<ref name=suzukietal2002>Suzuki, S., Chiappe, L. M., Dyke, G.J., Watabe, M., Barsbold, R., and Tsogtbaatar, K. (2002). "A new specimen of ''Shuvuuia deserti'' Chiappe et al., 1998 from the Mongolian Late Cretaceous with a discussion of the relationships of alvarezsaurids to other theropod dinosaurs." ''Contributions in Science'', '''494''': 1–18.</ref> However, these specimens have since been reclassified in the new genus ''[[Shuvuuia]]''.<ref name=chiappe>Chiappe, L. M., Norell, M. and Clark (1998). "The skull of a relative of the stem-group bird ''Mononykus''." ''Nature'', '''392''': 275–278.</ref> Because of this, many reconstructions of ''Mononykus'' in art and mounted skeletons in museums are in fact based mainly on ''Shuvuuia''. |
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| + | While ''Mononykus'' was formally described in the 1990s, it was reported that a specimen possibly belonging this genus had already been unearthed by the [[Roy Chapman Andrews|Andrews]] expedition decades before. The specimen had been in the [[American Museum of Natural History]] collection, labeled simply as "bird-like dinosaur".<ref name="DotG">{{cite video |date = 1993 |title = Dinosaurs of the Gobi |publisher = BBC Horizon |location = Mongolia}}</ref> However, given the reassignment of the other specimens to related genera, and the difference in age (the AMNH specimen is from the older [[Djadochta Formation]]), it is unlikely to be ''Mononykus''.<ref name="theropoddatabase">Mortimer, M. (2004), [http://archosaur.us/theropoddatabase/Ornithomimosauria.htm#Mononykusolecranus "Ornithomimosauria"], ''The Theropod Database'', accessed June 30, 2009.</ref> |
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| + | ==Paleobiology== |
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| + | ''Mononykus'' was a member of the family [[Alvarezsauridae]] and, like its relatives, had very strange, stubby forearms with one large, approximately {{convert|7.5|cm|in|adj=on}} long claw (hence its name). The other two claws had disappeared (however, a close relative of ''Mononykus'', ''[[Shuvuuia]]'', had two [[vestigial]] claws, alongside one large claw). The purpose of these highly specialized arms is still a mystery, but some scientists have suggested they were used to break open [[termite]] mounds (like modern [[anteaters]]), and therefore it is possible that they fed primarily on insects.<ref>Senter, P. (2005). "Function in the stunted forelimbs of ''Mononykus olecranus'' (Theropoda), a dinosaurian anteater". ''Paleobiology'' Vol. 31, No. 3 pp. 373–381.</ref> |
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| + | ''Mononykus'' is usually reconstructed with a covering of feathers. Indeed, in the fossil of its relative ''Shuvuuia'' feather traces were discovered, proving that Alvarezsauridae were among the theropod lineages with feathery or downy [[integument]].<ref name="schweitzer1999">Schweitzer, M. H., J. A. Watt, R. Avci, L. Knapp, L. Chiappe, M. Norell & M. Marshall. (1999). "Beta-keratin specific immunological reactivity in feather-like structures of the Cretaceous alvarezsaurid, ''Shuvuuia deserti''." ''Journal of Experimental Zoology'', '''285''': 146–157.</ref> |
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| + | In a 2001 study conducted by Bruce Rothschild and other paleontologists, 15 foot bones referred to ''Mononykus'' were examined for signs of [[stress fracture]], but none were found.<ref name="rothschild-dino">Rothschild, B., Tanke, D. H., and Ford, T. L., 2001, Theropod stress fractures and tendon avulsions as a clue to activity: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 331–336.</ref> |
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| + | ==References== |
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| + | {{Reflist|32em}} |
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| + | ==Further reading== |
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| + | *Haines, Tim and Paul Chambers. ''The Complete Guide to Prehistoric Life''. Pg. 125. Canada: Firefly Books Ltd., 2006. |
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| + | *{{cite video |date = 1993 |title = Dinosaurs of the Gobi |publisher = BBC Horizon |location = Mongolia}} |
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| + | ==External links==<!-- Auk114:300 --> |
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| + | *[http://www.dinosaur.net.cn/museum/Mononykus.htm In chinese but with pictures and taxon in english] |
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| + | . |
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[[Category:Dinosaurs of Asia]] |
[[Category:Dinosaurs of Asia]] |
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[[Category:Alvarezsaurs]] |
[[Category:Alvarezsaurs]] |
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[[Category:Small Carnivores]] |
[[Category:Small Carnivores]] |
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[[Category:Saurischia]] |
[[Category:Saurischia]] |
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[[Category:Reptiles]] |
[[Category:Reptiles]] |
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[[Category:Prehistoric Life]] |
[[Category:Prehistoric Life]] |
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[[Category:Carnivores]] |
[[Category:Carnivores]] |
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| + | [[Category:Cretaceous dinosaurs]] |
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| + | [[Category:Feathered dinosaurs]] |
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| + | [[Category:Cretaceous extinctions]] |
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| + | [[Category:Jurassic Park III: Park Builder Dinosaurs]] |
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| + | [[Category:Chased by Dinosaurs Creatures]] |
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| + | [[Category:Taxa named by Altangerel Perle]] |
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| + | [[Category:Fossil taxa described in 1993]] |
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| + | [[Category:Mongolian dinosaur]] |
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[[Category:Theropods]] |
[[Category:Theropods]] |
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| + | [[Category:Cretaceous theropods]] |
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| + | [[Category:Small Carnivore]] |
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| + | [[Category:Jurassic World: Fallen Kingdom dinosaurs]] |
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Revision as of 23:36, 11 February 2020
| Mononykus | |
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| Scientific classification |
Mononykus (/məˈnɒn[invalid input: 'ɨ']kəs/ Template:Respell, sometimes /ˌmɒn[invalid input: 'ɵ']ˈnaɪkəs/ Template:Respell; meaning "one claw") was a theropod dinosaur from late Cretaceous Mongolia (Nemegt Formation, about 70 million years ago) with long, skinny legs. It moved about on two legs, was likely very nimble and could run at high speeds, something that would have been useful in the open desert plains where it lived. It had a small skull, and its teeth were small and pointed, suggesting that it ate insects and small animals, such as lizards and mammals. Its large eyes might have allowed Mononykus to hunt by night, when it was cooler and there would have been fewer predators about. Mononykus was originally named Mononychus in 1993, but later that year, it was renamed because the original name had already been used for a beetle named by Johann Schueppel, a German entomologist.
Description
Mononykus was a small dinosaur, only 1 metre (3.3 ft) long. Other characteristics include fused wrist bones similar to those of birds, and a keeled breastbone. It differed from close relatives Shuvuuia and Parvicursor in several details of its skeleton, including a pubic bone that is triangular in cross section, and different proportions in the toe bones.
Mononykus is currently represented by a single holotype specimen, catalog number IGM N107/6. This specimen consists of a partial skeleton lacking a tail, and only small fragments of skull bones, including a complete braincase. Several other specimens were later misclassified as Mononykus, including specimens with partial tails (initially misinterpreted as being very short, though later specimens showed they were long and thin) and complete skulls showing a distinct, mostly toothless form.[1] However, these specimens have since been reclassified in the new genus Shuvuuia.[2] Because of this, many reconstructions of Mononykus in art and mounted skeletons in museums are in fact based mainly on Shuvuuia.
While Mononykus was formally described in the 1990s, it was reported that a specimen possibly belonging this genus had already been unearthed by the Andrews expedition decades before. The specimen had been in the American Museum of Natural History collection, labeled simply as "bird-like dinosaur".[3] However, given the reassignment of the other specimens to related genera, and the difference in age (the AMNH specimen is from the older Djadochta Formation), it is unlikely to be Mononykus.[4]
Paleobiology
Mononykus was a member of the family Alvarezsauridae and, like its relatives, had very strange, stubby forearms with one large, approximately 7.5-centimetre (3.0 in) long claw (hence its name). The other two claws had disappeared (however, a close relative of Mononykus, Shuvuuia, had two vestigial claws, alongside one large claw). The purpose of these highly specialized arms is still a mystery, but some scientists have suggested they were used to break open termite mounds (like modern anteaters), and therefore it is possible that they fed primarily on insects.[5]
Mononykus is usually reconstructed with a covering of feathers. Indeed, in the fossil of its relative Shuvuuia feather traces were discovered, proving that Alvarezsauridae were among the theropod lineages with feathery or downy integument.[6]
In a 2001 study conducted by Bruce Rothschild and other paleontologists, 15 foot bones referred to Mononykus were examined for signs of stress fracture, but none were found.[7]
References
- ↑ Suzuki, S., Chiappe, L. M., Dyke, G.J., Watabe, M., Barsbold, R., and Tsogtbaatar, K. (2002). "A new specimen of Shuvuuia deserti Chiappe et al., 1998 from the Mongolian Late Cretaceous with a discussion of the relationships of alvarezsaurids to other theropod dinosaurs." Contributions in Science, 494: 1–18.
- ↑ Chiappe, L. M., Norell, M. and Clark (1998). "The skull of a relative of the stem-group bird Mononykus." Nature, 392: 275–278.
- ↑ Template:Cite video
- ↑ Mortimer, M. (2004), "Ornithomimosauria", The Theropod Database, accessed June 30, 2009.
- ↑ Senter, P. (2005). "Function in the stunted forelimbs of Mononykus olecranus (Theropoda), a dinosaurian anteater". Paleobiology Vol. 31, No. 3 pp. 373–381.
- ↑ Schweitzer, M. H., J. A. Watt, R. Avci, L. Knapp, L. Chiappe, M. Norell & M. Marshall. (1999). "Beta-keratin specific immunological reactivity in feather-like structures of the Cretaceous alvarezsaurid, Shuvuuia deserti." Journal of Experimental Zoology, 285: 146–157.
- ↑ Rothschild, B., Tanke, D. H., and Ford, T. L., 2001, Theropod stress fractures and tendon avulsions as a clue to activity: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 331–336.
Further reading
- Haines, Tim and Paul Chambers. The Complete Guide to Prehistoric Life. Pg. 125. Canada: Firefly Books Ltd., 2006.
- Template:Cite video
External links
.