Name Meaning:  Ostrich Mimic
Geologic Era:  Late Cretaceous
Location Discovered:  Alberta, Canada
Range:  Canada to Wyoming
Size:  5 meters long
Extinction Date:  65 million years ago (K-T extinction)

Struthiomimus was one of the dinosaurs in the ornithomimid, or bird mimic group.  These animals had a superficial resemblance to modern ostriches, with long necks and legs.  These were animals well suited to running, as modern ostriches are.  Our bone come from the foot of Struthiomimus, probably from one of the more distal phallanges (toe bones).  Struthiomimus is well represented in the fossil record, with numerous complete skeletons having been found.  

Struthiomimus was first identified in the mid 1800’s, along with many other now well-known dinosaurs.  For many years, it was confused with Ornithomimus, a closely related species.  A few anatomical difference set Struthiomimus apart, such as concave beak structure and longer hands than its close relatives Ornithomimus and Gallimimus.  Ornithomimids had toothless beaks, much like modern birds do, and very large eyes.  Again, this brings to mind the modern ostrich.  Struthiomimus may have had a covering of feathers, though these would not have been used for flight.  

An analysis of Struthiomimus’ legs indicate that it could have sprinted up to 50 miles per hour, which would have made it difficult prey even for Tyrannosaurus rex.  Speed would probably have been its main defense, though it may have been able to kick with its hind claws as modern cassowaries do.  These claws could have inflicted serious injuries on a predator, and possibly would have made Struthiomimus undesirable prey.  Predators will expend as little energy as they can hunting prey, so a prey animal that can easily outrun or injure the predator might be passed over for slower, less defensible prey.  

Struthiomimus had a very unique hand structure.  Analysis of the digits show that it probably could not have moved its second and third fingers independently, and that the two may have been bound together by skin.  To approximate this on yourself, tape your ring and middle fingers together, and tuck in your thumb and pinkie.  You should effectively be left with two functioning digits.  

These hands probably would not have been terribly useful for grasping objects, but could have been used as a hook to pull branches toward mouth level.  Struthiomimus was probably mainly herbivorous, but like many modern birds, would have taken insects and small animals as well.  This diversity in diet would have served Struthiomimus well, as it would have allowed for less direct competition with true herbivores such as the hadrosaurs and ceratopsians.  

Image Credits:

Full Skeleton:  “Struthiomimus” by Credit to en:user:Ballista. Taken from the english wikipedia, uploaded here with the same license. – Own work. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Struthiomimus.JPG#/media/File:Struthiomimus.JPG


Life Restoration:  “Struthiomimus BW” by Nobu Tamura (http://spinops.blogspot.com) – Own work. Licensed under CC BY 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Struthiomimus_BW.jpg#/media/File:Struthiomimus_BW.jpg