Struthiomimus
Encyclopedia
Struthiomimus 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 (14.1 ft) long and 1.4 metres (4.6 ft) tall at the hips and weighed around 150 kilograms (330.7 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 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.
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 (14.1 ft) long and 1.4 metres (4.6 ft) tall at the hips, with a weight of around 150 kilograms (330.7 lb). 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, thirteen back vertebrae, six hip vertebrae, and about thirty-five tail vertebrae. The tail was stiff and was probably used for balance.
Struthiomimus had long slender arms and hands, with immobile forearm bones and limited opposability between the first finger and the other two. It had the longest hands relative to the humerus of any ornithomimid, with particularly long claws. The three fingers were roughly the same length, and the claws were only slightly curved; Henry Fairfield Osborn
, describing a skeleton in 1917, compared the arm to that of a sloth
. Its shin
was longer than its thigh
, a cursorial
feature. Among ornithomimids, though, its legs were only moderately elongate. Its feet were elongate, and the metatarsals were tightly appressed, with three toes tipped by claws with very slight curvature.
Struthiomimus, being a member of Coelurosauria
, probably had some kind of feather
s, especially if the Therizinosauria and the Alvarezsauridae
(of which at least one member, Shuvuuia
is known to have been feathered) are closely related.
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. Osborn complicated matters by assigning the better specimen, AMNH 5339, as the genoholotype. 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. In 1916 Osborn also renamed Ornithomimus tenuis Marsh 1890 into a Struthiomimus tenuis. This is today considered a nomen dubium
.
In subsequent years William Arthur Parks named four other species of Struthiomimus: Struthiomimus brevetertius Parks 1926, Struthiomimus samueli Parks 1928, Struthiomimus currellii Parks 1933 and Struthiomimus ingens Parks 1933. These are today seen as either belonging to Dromiceiomimus or to Ornithomimus.
In 1997 Donald Glut mentioned the name Struthiomimus lonzeensis. This was probably a lapsus calami, a mistake for Ornithomimus lonzeensis (Dollo 1903) Kuhn 1965.
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, in 2001 by James Orville Farlow named Struthiomimus sedens (again, originally named as a species of Ornithomimus by Marsh, in 1892).
In 2010 Gregory S. Paul
renamed Ornithomimus edmontonicus Sternberg 1933 into a Struthiomimus edmontonicus, but this has found no acceptance by other workers.
presented here follows the one recovered by Turner, Clarke, Ericson and Norell, 2007. Clade names follow definitions provided by Sereno, 2005.
Struthiomimus is a member of the family Ornithomimidae, a group which also includes Anserimimus
, Archaeornithomimus
, Dromiceiomimus, Gallimimus, Ornithomimus, and Sinornithomimus
.
Just as the fossil remains of Struthiomimus were incorrectly assigned to Ornithomimus, the larger group 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.
, but none were found.
There has been much discussion about the feeding habits of Struthiomimus. Because of its straight-edged beak, Struthiomimus may have been an omnivore
. Some theories suggest that it may have been a shore-dweller and may have been a filter feeder. Some paleontologists noted that it was more likely to be a carnivore because it is classified within the otherwise carnivorous theropod group. This theory has never been discounted, but Osborn, who described and named the dinosaur, proposed that it probably ate buds and shoots from trees, shrubs and other plants, using its forelimbs to grasp branches and its long neck to enable it accurately to select particular items. This herbivorous diet is further supported by the unusual structure of its hands. The second and third fingers were of equal length, could not function independently, 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 indicates that the hand was used as a "hook" or "clamp", for bringing branches or fern fronds at shoulder height within reach.
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 (31.1 to 49.7 mph).
Struthiomimus was one of the first theropods envisioned from the outset as having a horizontal posture. Osborn in 1916 let the animal intentionally be depicted with an elevated tail. This newer view created an image much more reminiscent of modern flightless birds, such as the ostrich to which this dinosaur's name refers, but would only much later be accepted for all theropods.
, 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.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of ornithomimid dinosaur from the late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
of Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. It was a long-legged, ostrich-like dinosaur.
The bipedal Struthiomimus stood about 4.3 metres (14.1 ft) long and 1.4 metres (4.6 ft) tall at the hips and weighed around 150 kilograms (330.7 lb). Struthiomimus is one of the more common small dinosaurs in the Dinosaur Provincial Park
Dinosaur Provincial Park
Dinosaur Provincial Park is a UNESCO World Heritage Site located about two and a half hours drive southeast of Calgary, Alberta, Canada or , about a half hour drive, northeast of Brooks....
; its abundance suggests that it was a herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
or omnivore
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
rather than a carnivore
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
.
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
Othniel Charles Marsh
Othniel Charles Marsh was an American paleontologist. Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of news species and theories on the origins of birds are among his legacies.Born into a modest family, Marsh was able to afford higher education...
in 1892, and a subsequent species was named O. altus by Lawrence Lambe
Lawrence Lambe
Lawrence Morris Lambe was a Canadian geologist and palaeontologist from the Geological Survey of Canada .His published work, describing the diverse and plentiful dinosaur discoveries from the fossil beds in Alberta, did much to bring dinosaurs into the public eye and helped usher in the Golden...
in 1902. It wasn't until 1917 that Henry Fairfield Osborn
Henry Fairfield Osborn
Henry Fairfield Osborn, Sr. ForMemRS was an American geologist, paleontologist, and eugenicist.-Early life and career:...
named Struthiomimus from fossils discovered in 1914 from the Red Deer River
Red Deer River
The Red Deer River is a river in Alberta, Canada. It is a major tributary of the South Saskatchewan River.Red Deer River has a total length of and a drainage area of...
site in Alberta.
Description
Ornithomimus
Ornithomimus is a genus of ornithomimid dinosaur from the Late Cretaceous Period of what is now North America.In 1890 Ornithomimus velox was named by Othniel Charles Marsh on the basis of a foot and partial hand from the Maastrichtian Denver Formation. Another seventeen species have been named since...
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 (14.1 ft) long and 1.4 metres (4.6 ft) tall at the hips, with a weight of around 150 kilograms (330.7 lb). 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, thirteen back vertebrae, six hip vertebrae, and about thirty-five tail vertebrae. The tail was stiff and was probably used for balance.
Struthiomimus had long slender arms and hands, with immobile forearm bones and limited opposability between the first finger and the other two. It had the longest hands relative to the humerus of any ornithomimid, with particularly long claws. The three fingers were roughly the same length, and the claws were only slightly curved; Henry Fairfield Osborn
Henry Fairfield Osborn
Henry Fairfield Osborn, Sr. ForMemRS was an American geologist, paleontologist, and eugenicist.-Early life and career:...
, describing a skeleton in 1917, compared the arm to that of a sloth
Sloth
Sloths are the six species of medium-sized mammals belonging to the families Megalonychidae and Bradypodidae , part of the order Pilosa and therefore related to armadillos and anteaters, which sport a similar set of specialized claws.They are arboreal residents of the jungles of Central and South...
. Its shin
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
was longer than its thigh
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
, a cursorial
Cursorial
Cursorial is a biological term that describes an organism as being adapted specifically to run. It is typically used in conjunction with an animal's feeding habits or another important adaptation. For example, a horse can be considered a "cursorial grazer", while a wolf may be considered a...
feature. Among ornithomimids, though, its legs were only moderately elongate. Its feet were elongate, and the metatarsals were tightly appressed, with three toes tipped by claws with very slight curvature.
Struthiomimus, being a member of Coelurosauria
Coelurosauria
Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...
, probably had some kind of feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s, especially if the Therizinosauria and the Alvarezsauridae
Alvarezsauridae
Alvarezsauridae is an enigmatic family of small, long-legged running dinosaurs. Although originally thought to represent the earliest known flightless birds, a consensus of recent work suggests that they are primitive members of the Maniraptora. Other work found them to be the sister group to the...
(of which at least one member, Shuvuuia
Shuvuuia
Shuvuuia is a genus of bird-like theropod dinosaur from the late Cretaceous period of Mongolia. It is a member of the family Alvarezsauridae, small coelurosaurian dinosaurs which are characterized by short but powerful forelimbs specialized for digging. The type species is Shuvuuia deserti, or...
is known to have been feathered) are closely related.
Discovery and species
In 1901, Lawrence LambeLawrence Lambe
Lawrence Morris Lambe was a Canadian geologist and palaeontologist from the Geological Survey of Canada .His published work, describing the diverse and plentiful dinosaur discoveries from the fossil beds in Alberta, did much to bring dinosaurs into the public eye and helped usher in the Golden...
found some incomplete remains, holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
CMN 930, and named them Ornithomimus
Ornithomimus
Ornithomimus is a genus of ornithomimid dinosaur from the Late Cretaceous Period of what is now North America.In 1890 Ornithomimus velox was named by Othniel Charles Marsh on the basis of a foot and partial hand from the Maastrichtian Denver Formation. Another seventeen species have been named since...
altus, placing them in the same genus as material earlier described by Othniel Charles Marsh
Othniel Charles Marsh
Othniel Charles Marsh was an American paleontologist. Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of news species and theories on the origins of birds are among his legacies.Born into a modest family, Marsh was able to afford higher education...
in 1890. The specific name altus is from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, meaning "lofty" or "noble". However, in 1914, a nearly complete skeleton was discovered by Barnum Brown
Barnum Brown
Barnum Brown , a paleontologist born in Carbondale, Kansas, and named after the circus showman P.T. Barnum, discovered the second fossil of Tyrannosaurus rex during a career that made him one of the most famous fossil hunters working from the late Victorian era into the early 20th century.Sponsored...
at the Red Deer River
Red Deer River
The Red Deer River is a river in Alberta, Canada. It is a major tributary of the South Saskatchewan River.Red Deer River has a total length of and a drainage area of...
site in Alberta, and officially described as the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Struthiomimus by Henry Fairfield Osborn
Henry Fairfield Osborn
Henry Fairfield Osborn, Sr. ForMemRS was an American geologist, paleontologist, and eugenicist.-Early life and career:...
in 1917. Osborn complicated matters by assigning the better specimen, AMNH 5339, as the genoholotype. Dale Russell
Dale Russell
Dale A. Russell is a Canadian geologist/palaeontologist, currently Research Professor at The Department of Marine Earth and Atmospheric Sciences of North Carolina State University...
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. In 1916 Osborn also renamed Ornithomimus tenuis Marsh 1890 into a Struthiomimus tenuis. This is today considered a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
.
In subsequent years William Arthur Parks named four other species of Struthiomimus: Struthiomimus brevetertius Parks 1926, Struthiomimus samueli Parks 1928, Struthiomimus currellii Parks 1933 and Struthiomimus ingens Parks 1933. These are today seen as either belonging to Dromiceiomimus or to Ornithomimus.
In 1997 Donald Glut mentioned the name Struthiomimus lonzeensis. This was probably a lapsus calami, a mistake for Ornithomimus lonzeensis (Dollo 1903) Kuhn 1965.
Struthiomimus altus comes from the Late Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
(Judithian age) Dinosaur Park Formation
Dinosaur Park Formation
The Dinosaur Park Formation is the uppermost member of the Judith River Group, a major geologic unit in southern Alberta. It was laid down over a period of time between about 76.5 and 75 million years ago. The formation is made up of deposits of a high-sinuosity fluvial system, and is capped...
. A species of Struthiomimus is also known from the Late Campanian/Early Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
(Edmontonian age) Horseshoe Canyon Formation
Horseshoe Canyon Formation
The Horseshoe Canyon Formation is part of the Edmonton Group and is up to 230m in thickness. It is Late Campanian to Early Maastrichtian in age and is composed of mudstone, sandstone, and carbonaceous shales...
. 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
Hell Creek Formation
The Hell Creek Formation is an intensely-studied division of Upper Cretaceous to lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana...
are larger (similar to Gallimimus
Gallimimus
Gallimimus is a genus of ornithomimid theropod dinosaur from the late Cretaceous period Nemegt Formation of Mongolia. With individuals as long as , it was one of the largest ornithomimosaurs...
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, in 2001 by James Orville Farlow named Struthiomimus sedens (again, originally named as a species of Ornithomimus by Marsh, in 1892).
In 2010 Gregory S. Paul
Gregory S. Paul
Gregory Scott Paul is a freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal...
renamed Ornithomimus edmontonicus Sternberg 1933 into a Struthiomimus edmontonicus, but this has found no acceptance by other workers.
Classification
The cladogramCladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
presented here follows the one recovered by Turner, Clarke, Ericson and Norell, 2007. Clade names follow definitions provided by Sereno, 2005.
Struthiomimus is a member of the family Ornithomimidae, a group which also includes Anserimimus
Anserimimus
Anserimimus is a genus of ornithomimid theropod dinosaur, from the Late Cretaceous Period of what is now Mongolia. It was a lanky, fast-running animal, possibly an omnivore...
, Archaeornithomimus
Archaeornithomimus
Archaeornithomimus is a genus of ornithomimosaurian theropod dinosaur from the Late Cretaceous of China, 70 million years ago....
, Dromiceiomimus, Gallimimus, Ornithomimus, and Sinornithomimus
Sinornithomimus
Sinornithomimus is a genus of ornithomimid theropod dinosaur found in 1997, in the early Late Cretaceous strata of the Ulansuhai Formation located at Alshanzuo Banner, Nei Mongol Autonomous Region, Northern China.-Discovery and naming:...
.
Just as the fossil remains of Struthiomimus were incorrectly assigned to Ornithomimus, the larger group that Struthiomimus belongs to, the Ornithomimosauria
Ornithomimosauria
The Ornithomimosauria, ornithomimosaurs or ostrich dinosaurs were theropod dinosaurs which bore a superficial resemblance to modern ostriches. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia...
, 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
Ceratosauria
Ceratosaurs are members of a group of theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. There is presently no universally agreed upon listing of species or diagnostic characters of Ceratosauria, though they were less derived...
. In 1891, Baur placed the genus within Iguanodontia. As late as 1993, Struthiomimus was referred to Oviraptorosauria
Oviraptorosauria
Oviraptorosaurs are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot - like skulls, with or without bony crests atop the head...
. 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
Paul Sereno
Paul Callistus Sereno is an American paleontologist from the University of Chicago who discovered several new dinosaur species on several continents. He has conducted excavations at sites as varied as Inner Mongolia, Argentina, Morocco, and Niger...
, 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.
Paleobiology
In a 2001 study conducted by Bruce Rothschild and other paleontologists, fifty foot bones referred to Struthiomimus were examined for signs of stress fractureStress fracture
A stress fracture is one type of incomplete fracture in bones. It is caused by "unusual or repeated stress" and also heavy continuous weight on the ankle or leg...
, but none were found.
Diet
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
. Some theories suggest that it may have been a shore-dweller and may have been a filter feeder. Some paleontologists noted that it was more likely to be a carnivore because it is classified within the otherwise carnivorous theropod group. This theory has never been discounted, but Osborn, who described and named the dinosaur, proposed that it probably ate buds and shoots from trees, shrubs and other plants, using its forelimbs to grasp branches and its long neck to enable it accurately to select particular items. This herbivorous diet is further supported by the unusual structure of its hands. The second and third fingers were of equal length, could not function independently, 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 indicates that the hand was used as a "hook" or "clamp", for bringing branches or fern fronds at shoulder height within reach.
Speed
Saurornitholestes
Saurornitholestes is a genus of carnivorous dromaeosaurid theropod dinosaur from the late Cretaceous of Alberta, Montana and New Mexico....
and Dromaeosaurus
Dromaeosaurus
Dromaeosaurus was a genus of theropod dinosaur which lived during the Late Cretaceous period , sometime between 76.5 and 74.8 million years ago, in the western United States and Alberta, Canada. The name means 'running lizard'....
) and tyrannosaurs (e.g. Daspletosaurus
Daspletosaurus
Daspletosaurus is a genus of tyrannosaurid theropod dinosaur that lived in western North America between 77 and 74 million years ago, during the Late Cretaceous Period. Fossils of the only named species were found in Alberta, although other possible species from Alberta and Montana await...
and Gorgosaurus
Gorgosaurus
Gorgosaurus is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, between about 76.5 and 75 million years ago. Fossil remains have been found in the Canadian province of Alberta and possibly the U.S. state of Montana....
), which lived at the same time. It is estimated to have been able to run at speeds between 50 to 80 km/h (31.1 to 49.7 mph).
Posture
Popular culture
The best-preserved skeleton of Struthiomimus is currently on display at the American Museum of Natural HistoryAmerican Museum of Natural History
The American Museum of Natural History , located on the Upper West Side of Manhattan in New York City, United States, is one of the largest and most celebrated museums in the world...
, in Manhattan
Manhattan
Manhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...
, New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
, while the best-preserved skull is currently on display at the Royal Tyrrell Museum of Palaeontology
Royal Tyrrell Museum of Palaeontology
The Royal Tyrrell Museum is a popular Canadian tourist attraction and a leading centre of palaeontological research noted for its collection of more than 130,000 fossils....
, in Drumheller
Drumheller, Alberta
Drumheller is a town within the Red Deer River valley in the badlands of east-central Alberta, Canada. It is located northeast of Calgary...
, Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
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
The Land Before Time II: The Great Valley Adventure
The Land Before Time II: The Great Valley Adventure, is a 1994 direct-to-video animated film directed by Roy Allen Smith, is the first of many animated sequels to the film The Land Before Time. It was released six years after the original.The tone, lighting and plot of the film was made much softer...
. They played a prominent role in the Disney animated film Dinosaur
Dinosaur (film)
Dinosaur is a 2000 American computer-animated film produced by Walt Disney Feature Animation and released by Walt Disney Pictures on May 19, 2000, and is the 39th animated feature in the Walt Disney Animated Classics series...
, and in 1985, Struthiomimus was featured in Dinosaur!
Dinosaur!
Dinosaur! is an American television documentary about dinosaurs. It was first aired on CBS in the United States on November 5, 1985. Years later, in 1991, another documentary entitled Dinosaur!, not related with that one, was hosted on A&E by CBS anchorman Walter Cronkite.-Content:Directed by...
, a CBS television documentary hosted by Christopher Reeve
Christopher Reeve
Christopher D'Olier Reeve was an American actor, film director, producer, screenwriter, author and activist...
. 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
Deinonychus
Deinonychus was a genus of carnivorous dromaeosaurid dinosaur. There is one described species, Deinonychus antirrhopus. This 3.4 meter long dinosaur lived during the early Cretaceous Period, about 115–108 million years ago . Fossils have been recovered from the U.S...
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
Dino-Riders
Dino-Riders is a cartoon television series that first aired in 1988. Dino-Riders was primarily a promotion to launch a new Tyco toy line. Only fourteen episodes were produced, three of which were produced on VHS for the United States. It aired in the U.S...
line by Tyco and was later re-released in the Smithsonian toy line.