Struthiomimus (meaning "ostrich mimic", from the Greek στρούθειος/stroutheios meaning "of the ostrich" and μῖμος/mimos meaning "mimic" or "imitator") is a genus of ornithomimid dinosaur from the late Cretaceous of Alberta. It was a long-legged, ostrich-like dinosaur with toothless beaks.
The bipedal Struthiomimus stood about 14 ft long and 4.6 ft tall at the hips and weighed around 330 pounds.[1] The genus Struthiomimus currently contains three species.[2] The most well-known species, Struthiomimus is one of the more common small dinosaurs in the Provincial Park; its abundance suggests that it was a herbivore or omnivore rather than a carnivore. [3]
Like many other dinosaur genera discovered in the 19th century, the history of Struthiomimus is convoluted. The first known fossils of Struthiomimus were named Ornithomimus sedens by Othniel Charles Marsh in 1892, and a subsequent species was named O. altus by Lawrence Lambe in 1902. It wasn't until 1917 that Henry Fairfield Osborn named Struthiomimus from fossils discovered in 1914 from the Red Deer River site in Alberta.
A long, slender, flexible neck made it easy to pick up seeds and seize small animals.
Description[]
Life restoration of S. altus
Struthiomimus had a typical build and skeletal structure for an ornithomimid, differing from genera like Ornithomimus and Dromiceiomimus in size and anatomical details.[4] It is known from some skeletons and skulls,[5] and its size is about 14 ft long and 4.6 ft tall at the hips, with a weight of around 330 pounds. [6] As with other ornithomimids, it had a small slender head on a long neck (which made up about 40% of the length of the body in front of the hips).[5] Its eyes were large and its jaws had no teeth. Its spine had 10 neck vertebrae, 13 back vertebrae, 6 hip vertebrae, and about 35 tail vertebrae.[7] The tail was stiff and was likely used for balance.[8]
Size comparison between S. altus and S. sedens
Struthiomimus had long arms and hands, with still forearm bones and limited opposability between the first finger and the other two.[9] It had the longest hands of any ornithomimid, with particularly long claws.[5] The three fingers were roughly the same length, and the claws had a slight curve; Henry Fairfield Osborn, describing a skeleton in 1917, said the arm was like that of a sloth.[8] Its shin was longer than its thigh, a feature for running.[8] Among ornithomimids, though, its legs were of moderate length. [10] Its feet were long, with three toes tipped by claws with a slight curve.[8]
Struthiomimus, being a relative of the definitely plumed Ornithomimus, was most likely feathered to some extent.
Struthiomimus differed from close relatives only in subtle aspects of anatomy. The edge of the upper beak was concave in Struthiomimus, unlike Ornithomimus, which had straight beak edges.[2] Struthiomimus had longer hands relative to the humerus than other ornithomimids, with particularly long claws.[5] Their forelimbs were more robust than in the similar Ornithomimus.[2]
Species[]
The type species, S. altus, is known from several skeletons and skulls,[5] and its size is estimated as about 4.3 metres (14 ft) long and 1.4 metres (4.6 ft) tall at the hips, with a weight of around 150 kilograms (330 lb).[11] Fossil remains of S. altus are only known definitively from the Dinosaur Park Formation, dated to about 75 million years ago during the Campanian stage of the late Cretaceous period.[2] A younger species (which has not yet been named), which apparently differed from S. altus in having longer, more slender hands, is known from several specimens found in the Horseshoe Canyon Formation, dated to about 70 million years ago (early Maastrichtian).[2] A third, even younger species, S. sedens, is known from the late Maastrichtian Lance Formation and Hell Creek Formation, dated to about 66 million years ago. S. sedens is also the largest Struthiomimus, similar to Gallimimus in size,[2] and measuring about 5 metres (16 ft) in length.[12]
History[]
Cast of S. altus skeleton (specimen AMNH 5339), found in 1914
In 1901, Lawrence Lambe found some incomplete remains, holotype CMN 930, and named them Ornithomimus altus, placing them in the same genus as material earlier described by Othniel Charles Marsh in 1890. The specific name altus is from Latin, meaning "lofty" or "noble". However, in 1914, a nearly complete skeleton was discovered by Barnum Brown at the Red Deer River site in Alberta, and officially described as the subgenus Struthiomimus by Henry Fairfield Osborn in 1917.[13] Osborn complicated matters by assigning the better specimen, AMNH 5339, as the genoholotype.[8] Dale Russell made Struthiomimus a full genus in 1972, at the same time referring several other specimens to it: AMNH 5375, AMNH 5385, AMNH 5421, CMN 8897, CMN 8902 en ROM 1790, all partial skeletons.[14] In 1916 Osborn also renamed Ornithomimus tenuis Marsh 1890 into a Struthiomimus tenuis.[8] This is today considered a nomen dubium.
In subsequent years William Arthur Parks named four other species of Struthiomimus: Struthiomimus brevetertius Parks 1926,[15] Struthiomimus samueli Parks 1928,[16] Struthiomimus currellii Parks 1933 and Struthiomimus ingens Parks 1933.[17] These are today seen as either belonging to Dromiceiomimus or to Ornithomimus.
Skeletal diagram of S. altus specimen AMNH 5339
In years to come William Arthur Parks named four more species of Struthiomimus: Struthiomimus brevetertius Parks 1926,[18] Struthiomimus samueli Parks 1928,[19] Struthiomimus currellii Parks 1933 and Struthiomimus ingens Parks 1933.[20] These are now thought to either come from to Dromiceiomimus or to Ornithomimus.
Cast of BHI 1266, which may be a Struthiomimus sedens specimen
In 1997 Donald Glut mentioned the name Struthiomimus lonzeensis.[21] This was probably a mistake for Ornithomimus lonzeensis (Dollo 1903) Kuhn 1965. Struthiomimus altus comes from the Dinosaur Park Formation and a species of Struthiomimus is known from the Horseshoe Canyon Formation.[2] Since dinosaur fauna show rapid turnover, it could be that these younger Struthiomimus specimens will prove to be a species distinct from S. altus, though they have no new name. Struthiomimus specimens from the Hell Creek Formation are larger (similar to Gallimimus in size) and tend to have straighter and longer hand claws, like those seen in Ornithomimus. They most likely represent a separate species of Struthiomimus, in 2001 by James Orville Farlow named Struthiomimus sedens[22] (again, first named as a species of Ornithomimus by Marsh, in 1892).[2][23]
In 2010 Gregory S. Paul renamed Ornithomimus edmontonicus Sternberg 1933 to a Struthiomimus edmontonicus,[24] but this has found no acceptance by other workers.
Classification[]
Original skull of RTMP 1990.026.0001 in A, C and E and restored in B, D and F
Struthiomimus is a member of the family Ornithomimidae, a group which also includes Anserimimus, Archaeornithomimus, Dromiceiomimus, Gallimimus, Ornithomimus, and Sinornithomimus.
Just as the bones of Struthiomimus were wrongly assigned to Ornithomimus, the larger group that Struthiomimus belongs to, the Ornithomimosauria, also went thorugh many changes over the years. For example, O.C. Marsh at first included Struthiomimus in the Ornithopoda, a large clade of dinosaurs not closely related to theropods. [25] Five years later, Marsh classified Struthiomimus in the Ceratosauria. [26] [27] In 1891, Baur placed the genus in Iguanodontia.[28] As late as 1993, Struthiomimus was referred to Oviraptorosauria.[29] However, by the 1990s, there were a lot of studies that placed Struthiomimus in Coelurosauria.[30][31][32][33]
In 1976, Rinchen Barsbold saw the difference between ornithomimids and other theropods, and placed ornithomimids in their own infraorder, Ornithomimosauria.[34] The constituency of Ornithomimidae and Ornithomimosauria varied with different authors. Paul Sereno, for example, used Ornithomimidae to include all ornithomimosaurians in 1998, but subsequently changed to a more exclusive definition (advanced ornithomimosaurs) within Ornithomimosauria,[35] a classification scheme that other authors took up at the beginning of the current century.
The cladogram follows the 2011 analysis by Xu et al.:[36]
| Ornithomimidae |
| ||||||||||||||||||||||||||||||||||||
Paleobiology[]
In a 2001 study conducted by Bruce Rothschild and other paleontologists, fifty foot bones referred to Struthiomimus were examined for signs of stress fracture, but none were found.[37]
Diet[]
Reconstructed skull, Royal Belgian Institute of Natural Sciences, Brussels
There has been much talk of what Struthiomimus ate. Its straight-edged beak shows that Struthiomimus may have been an omnivore. Some theories suggest that it may have shore-dweller and may have been a filter feeder. [38] Some paleontologists note that it was more likely that it ate meat as it is classified in the otherwise meat-eating theropod group. [39] [40]This theory has not been discounted, but Osborn, who described and named the dinosaur, proposed that it probably ate buds and shoots from trees, shrubs and other plants, [41]using its front limbs to grasp branches and its long neck to let it take particular things. This plant-based diet is backed up by the strange structure of its hands. The second and third fingers were of the same length, could not work on their own, and were probably bound together by skin as a single unit. The structure of the shoulder girdle did not allow a high elevation of the arm nor was optimised for a low reach. The hand could not be fully flexed for a grasping motion or spread for raking. This is a sign that the hand was used as a "hook" or "clamp", to bring branches or fern fronds at shoulder height within reach. [42]
Speed[]
The legs (hind limbs) of Struthiomimus were long, strong, and seemed to be well-suited to run fast, much like an ostrich. The supposed speed of Struthiomimus was, in fact, its main defense from predators (though it may also have been able to lash out with its hind claws when trapped), such as the dromaeosaurids (e.g. Saurornitholestes and Dromaeosaurus) and tyrannosaurs (e.g. Daspletosaurus and Gorgosaurus), which lived at the same time. It is thought to have been able to run at speeds from 31 to 50 mph. [43]
Posture[]
Struthiomimus was one of the first theropods pictured from the start with a horizontal posture. Osborn in 1916 let the animal intentionally be drawn with a raised tail. [44]This newer view created an image much more similar to modern flightless birds, such as the ostrich to which this dinosaur's name comes from, but would only much later be accepted for all theropods.
Paleoecology[]
Struthiomimus lived in North America during the Late Cretaceous period around 83 to 66 million years ago. It lived alongside a range of many other dinosaurs, including the hadrosaur Edmontosaurus, the pachycephalosaurs Pachycephalosaurus, Stygimoloch, and Dracorex, the ceratopsians Triceratops and Torosaurus, the armored Ankylosaurus, as well as the theropods Troodon and the feared apex predator Tyrannosaurus.
Sites where Struthiomimus have been found show a remarkable diversity in animal and plant life. There is evidence of freshwater animals, indicating water bodies like rivers and lakes.
JPInstitute.com Description[]
Struthiomimus was a speedy predator with long legs. It is called an ostrich mimic because it probably moved like a modern ostrich. Like other meat-eaters in its family, Struthiomimus had no teeth. It had a very small head, long arms and long grasping hands.
Unfortunately, the Struthiomimus type specimen that was found in 1902 was damaged very badly. Since that time, however, a number of other specimens have been discovered, but none are convincingly complete enough to resolve the ongoing debate of whether this dinosaur should be classified as Ornithomimus. Several specimens originally attached to this genus have been reclassified to other genera.
The diet of these dinosaurs has been the subject of debate for a number of years. Since they were toothless, various diet theories have been put forward. It has been suggested that the hands and slight build of this creature suggest that it ate mainly insects, but other scientists are firm in their belief that Struthiomimus and its family members were strictly carnivorous.
Appearance in other media[]
Jurassic Park[]
- Struthomimus has been confirmed to appear in Jurassic World: Evolution. It is the first dinosaur species that players get in their parks. The main skin is mainly brown with a white underbelly, arms, neck and head, and darker brown stripes all over the sides of the dinosaur and a faint blue on the top of the head just behind the eye. It is inaccurately depicted as a herbivore, when it, in real life, is an omnivore. This is possibly due to their limitations that resemble a herbivore.
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Read more Struthiomimus on Jurassic Park Wiki |
The Land Before Time[]
- They also made a some appearances in The Land Before Time film series, two in particular Ozzy and Strut are the main villains in the second movie.
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Read more Struthiomimus on Land Before Time Wiki |
Links[]
References[]
- ↑ Paul, Gregory S. (1988). "Ornithomimus altus". Predatory Dinosaurs of the World. New York: Simon & Schuster. pp. 387–389. ISBN 0-671-61946-2.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Longrich, N. (2008). "A new, large ornithomimid from the Cretaceous Dinosaur Park Formation of Alberta, Canada: Implications for the study of dissociated dinosaur remains." Palaeontology, 51(4): 983-997. Cite error: Invalid
<ref>tag; name "longrich2008" defined multiple times with different content - ↑ Barrett, Paul M. (2005). "The diet of ostrich dinosaurs (Theropoda: Ornithomimosauria)". Palaeontology 48 (2), 347–358. DOI:10.1111/j.1475-4983.2005.00448.x
- ↑ Template:Cite book
- ↑ 5.0 5.1 5.2 5.3 5.4 Template:Cite book Cite error: Invalid
<ref>tag; name "PJC05" defined multiple times with different content - ↑ Paul, Gregory S. (1988). "Ornithomimus altus". Predatory Dinosaurs of the World. New York: Simon & Schuster. pp. 387–389. ISBN 0-671-61946-2.
- ↑ Template:Cite book
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Template:Cite journal
- ↑ Template:Cite journal
- ↑ Paul, Gregory S. (1988). "Ornithomimus altus". Predatory Dinosaurs of the World. New York: Simon & Schuster. pp. 387–389. ISBN 0-671-61946-2.
- ↑ Template:Cite book
- ↑ Holtz, Thomas R. Jr. (2012) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2011 Appendix.
- ↑ Osborn, Henry Fairfield (1917). "Skeletal adaptations of Ornitholestes, Struthiomimus, Tyrannosaurus" (pdf). Bulletin of the American Museum of Natural History 35: 733–771.
- ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedR72 - ↑ Parks, W.A., 1926, "Struthiomimus brevetertius - A new species of dinosaur from the Edmonton Formation of Alberta", Transactions of the Royal Society of Canada, series 3. 20(4): 65-70
- ↑ Parks, W.A., 1928, "Struthiomimus samueli, a new species of Ornithomimidae from the Belly River Formation of Alberta", University of Toronto Studies, Geology Series. 26: 1-24
- ↑ Parks, W.A., 1933, "New species of dinosaurs and turtles from the Upper Cretaceous formations of Alberta", University of Toronto Studies, Geological Series, 34: 1-33
- ↑ Parks, W.A., 1926, "Struthiomimus brevetertius - A new species of dinosaur from the Edmonton Formation of Alberta", Transactions of the Royal Society of Canada, series 3. 20(4): 65-70
- ↑ Parks, W.A., 1928, "Struthiomimus samueli, a new species of Ornithomimidae from the Belly River Formation of Alberta", University of Toronto Studies, Geology Series. 26: 1-24
- ↑ Parks, W.A., 1933, "New species of dinosaurs and turtles from the Upper Cretaceous formations of Alberta", University of Toronto Studies, Geological Series, 34: 1-33
- ↑ Glut, D., 1997, Dinosaurs - The Encyclopedia. McFarland Press, Jefferson, NC. 1076 pp
- ↑ Farlow, J.O., 2001, "Acrocanthosaurus and the maker of Comanchean large-theropod footprints", In: Tanke, Carpenter, Skrepnick and Currie (eds). Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie. pp. 408-427
- ↑ Marsh, O.C. (1892). "Notice of new reptiles from the Laramie Formation." American Journal of Science, Series 3, 43: 449–453.
- ↑ Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press, p. 117
- ↑ O. C. Marsh. 1890. Additional characters of the Ceratopsidae, with notice of new Cretaceous dinosaurs. American Journal of Science 39:418-426
- ↑ O. C. Marsh. 1895. On the affinities and classification of the dinosaur reptiles. American Journal of Science.
- ↑ O. C. Marsh. 1896. The dinosaurs of North America. United States Geological Survey, 16th Annual Report, 1894-95 55:133-244
- ↑ G. Baur. 1891. Remarks on the reptiles generally called Dinosauria. The American Naturalist 25 (293) :434-454
- ↑ D. A. Russell and Z.-M. Dong. 1993. The affinities of a new Theropod from the Alxa Desert, Inner Mongolia, People's Republic of China. Canadian Journal of Earth Sciences 30 (10-11) :2107-2127
- ↑ J. A. Gauthier and K. Padian. 1985. Phylogenetic, functional, and aerodynamic analyses of the origin of birds and their flight. In M. K. Hecht, J. H. Ostrom, G. Viohl, and P. Wellnhofer (eds.), The Beginnings of Birds: Proceedings of the International Conference Archaeopteryx, Eichstätt 1984. Freunde des Jura-Museums Eichstätt, Eichstätt 185-197
- ↑ F. E. Novas. 1992. The evolution of carnivorous dinosaurs. In J. L. Sanz and A. D. Buscalioni (eds.), The Dinosaurs and Their Environment Biotic: Proceedings of the Second Year of Paleontology in Cuenca. Institute "Juan Valdez", Cuenca, Argentina 126-163
- ↑ P. C. Sereno, J. A. Wilson, H. C. E. Larsson, D. B. Dutheil, and H.-D. Sues. 1994. Early Cretaceous dinosaurs from the Sahara. Science 266 (5183) :267-271
- ↑ P. J. Makovicky, Y. Kobayashi, and P. J. Currie. 2004. Ornithomimosauria. In D. B. Weishampel, P. Dodson, & H. Osmólska (eds.), The Dinosauria (second edition). University of California Press, Berkeley 137-150
- ↑ R. Barsbold. 1976. K evolyutsii i sistematike pozdnemezozoyskikh khishchnykh dinozavrov [The evolution and systematics of late Mesozoic carnivorous dinosaurs]. In N. N. Kramarenko, B. Luvsandansan, Y. I. Voronin, R. Barsbold, A. K. Rozhdestvensky, B. A. Trofimov & V. Y. Reshetov (eds.), Paleontology and Biostratigraphy of Mongolia. The Joint Soviet-Mongolian Paleontological Expedition, 3:68-75 Transactions
- ↑ P.C. Sereno. 1998. A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 210 (1) :41-83
- ↑ Template:Cite journal
- ↑ 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.
- ↑ Makovicky, Peter J.; Kobayashi, Yoshitsugu; and Currie, Philip J. (2004). "Ornithomimosauria". In Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 137–150. ISBN 0-520-24209-2.
- ↑ Osmólska H, Roniewicz E & Barsbold R (1972). "A new dinosaur, Gallimimus bullatus n. gen.,n. sp. (Ornithomimidae) from the Upper Cretaceous of Mongolia". Paleontol. Polonica 27: 103–143.
- ↑ Russell D (1972). "Ostrich dinosaurs from the Late Cretaceous of Western Canada". Canadian Journal of Earth Sciences 9 (4): 375–402. doi:10.1139/e72-031.
- ↑ Paul, Gregory S. (1988). "Genus Ornithomimus". Predatory Dinosaurs of the World. New York: Simon & Schuster. pp. 384–394. ISBN 0-671-61946-2.
- ↑ Nicholls, Elizabeth L.; and Russell, Anthony P. (1985). "Structure and function of the pectoral girdle and forelimb of Struthiomimus altus (Theropoda: Ornithomimidae)". Palaeontology 28: 643–677.
- ↑ Paul, regarding his comparative speed estimates, notes that "... just how swift is swift? In hard, precise measure, this can be a real can of worms; for just how fast living animals run is not well known." (Paul, G.S. 1988. Predatory Dinosaurs of the World. New York: Simon & Schuster.)
- ↑ Osborn, Henry Fairfield (1917). "Skeletal adaptations of Ornitholestes, Struthiomimus, Tyrannosaurus" (pdf). Bulletin of the American Museum of Natural History 35: 733–771.