Old Earth Ministries Online Dinosaur Curriculum
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Lesson 28 - Struthiomimus
Struthiomimus (meaning "ostrich mimic", from the Greek) is a genus of ornithomimid dinosaur from the late Cretaceous of Alberta, Canada. It was a long-legged, ostrich-like dinosaur.
The bipedal Struthiomimus stood about 4.3 metres (14 ft) long and 1.4 metres (4.6 ft) tall at the hips and weighed around 150 kilograms (330 lb). Struthiomimus is one of the more common small dinosaurs in the Dinosaur Provincial Park; its abundance suggests that it was a herbivore or omnivore rather than a carnivore.
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
Marsh in 1892, and a subsequent species was named
O. altus by
Lawrence Lambe in
1902. It wasn't until 1917 that
Fairfield Osborn named
Struthiomimus from fossils discovered in
1914 from the
River site in Alberta.
Struthiomimus had a typical build and skeletal structure for an ornithomimid, differing from genera like Ornithomimus and Dromiceiomimus in proportions and anatomical details. It is known from several skeletons and skulls, 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).
Length: 14 Ft
Height: 4.6 Ft at hip
Weight: 330 lbs
Date Range: ~75 Ma, Campanian Age, Cretaceous Period
|Struthiomimus sedens skeleton in the Oxford University Museum of Natural History (Picture Source)|
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). Its eyes were large and its jaws were toothless. Its vertebral column had ten neck vertebrae, sixteen back vertebrae, six hip vertebrae, and an unknown number of tail vertebrae. The tail was stiff and was probably used for balance.
Struthiomimus had long slender arms and hands, with immobile forearm bones but limited
Struthiomimus, being a member of Coelurosauria, probably had feathers, especially if the Ornithomimosauria and the alvarezsauridae (of which at least one member, Shuvuuia is known to have been feathered) are closely related.
Discovery and species
In 1901, Lawrence Lambe found some incomplete remains and named them
Struthiomimus altus comes from the Late Campanian (Judithian age) Dinosaur Park Formation. A species of Struthiomimus is also known from the Late Campanian/Early Maastrichtian (Edmontonian age) Horseshoe Canyon Formation. Because dinosaur fauna show rapid turnover, it is possible that these younger Struthiomimus specimens will prove to be a species distinct from S. altus, though no new name has been given to them. Struthiomimus specimens from the Hell Creek Formation are larger (similar to Gallimimus in size) and tend to have straighter and more elongate hand claws, similar to those seen in Ornithomimus. They most likely represent a separate species of Struthiomimus, named Struthiomimus sedens (again, originally named as a species of Ornithomimus by Marsh, in 1892).
Just as the fossil remains of Struthiomimus were incorrectly assigned to Ornithomimus, the superfamily that Struthiomimus belongs to, the Ornithomimosauria, also underwent many changes over the years. For example, O.C. Marsh initially included Struthiomimus in the Ornithopoda, a large clade of dinosaurs not closely related to theropods. Five years later, Marsh classified Struthiomimus in the Ceratosauria. In 1891, Baur placed the genus within Iguanodontia. As late as 1993, Struthiomimus was referred to Oviraptorosauria. However, by the 1990s, there were numerous studies that placed Struthiomimus within Coelurosauria.
Recognizing the difference between ornithomimids and other theropods, Rinchen Barsbold placed ornithomimids within their own infraorder, Ornithomimosauria, in 1976. 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, a classification scheme that was adopted by other authors at the beginning of the current century.
There has been much discussion about the feeding habits of Struthiomimus. Because of its
The legs (hind limbs) of Struthiomimus were long, powerful and seemingly well-suited to rapid running, much like an ostrich. The supposed speed of Struthiomimus was, in fact, its main defense from predators (although it may also have been able to lash out with its hind claws when cornered), such as the dromaeosaurids (e.g. Saurornitholestes and Dromaeosaurus) and tyrannosaurs (e.g. Daspletosaurus and Gorgosaurus), which lived at the same time. It is estimated to have been able to run at speeds between 50 to 80 km/h (31 to 50 mph).
Early restorations depict a posture reminiscent of the "walking tripod" postures of Tyrannosaurus and Iguanodon, before the later, more balanced depictions with stiffened horizontal tails and bodies were widely accepted. This newer view creates an image much more reminiscent of modern flightless birds, such as the ostrich to which this dinosaur's name refers.
The best-preserved skeleton of Struthiomimus is currently on display at the American Museum of Natural History, in Manhattan, New York, while the best-preserved skull is currently on display at the Royal Tyrrell Museum of Palaeontology, in Drumheller, Alberta, Canada.
Struthiomimus has appeared in several dinosaur-related films and television programs, such as the pair of bumbling egg-napping villains in The Land Before Time II: The Great Valley Adventure. They played a prominent role in the Disney animated film Dinosaur, and in 1985, Struthiomimus was featured in Dinosaur!, a CBS television documentary hosted by Christopher Reeve. In a stop-motion animation sequence, a Struthiomimus was shown feeding on hadrosaurid eggs and escaping the angry mother, only to be preyed upon by a pair of Deinonychus moments later (though in reality, Deinonychus lived in the early Cretaceous Period and was not a contemporary of Struthiomimus). Struthiomimus toys were included in the Dino-Riders line by Tyco and was later re-released in the Smithsonian toy line.
If you ordered the Test Pack, it is now time to take Test 4.
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Bay State Replicas - Full skeleton
Black Hills Institute - Full skeleton, skeleton in matrix, skull, arm, hand, claw, foot