Despite the often very theropod-centric nature of the Musings, some groups still end up rather unrepresented. While I did try to cover the ornithomimosaurs in more detail a few months back, they have still never had much of a look in on here. Following on from the popularity of the Triceratops post then and with more photos from the Oxford museum, here’s some details of Struthiomimus.
Dave Hone's Archosaur Musings 
Thanks for the pics! This is S. sedens, not S. altus right? There seems to be some questioning whether this actually belongs to Struthiomimus, or to Ornithomimus as originally described, or deserves a separate genus. Miker Mortimer finds it closer to Archaeornithomimus than to Ornithomimus or Struthiomimus. http://home.comcast.net/~eoraptor/Ornithomimosauria.htm#Ornithomimussedens
I have no idea. The label didn’t say where it was from or what it was based on or give the species, and I wouldn’t know how to tell them apart in any case without reading up on it so your guess is probably better than mine.
Is that supposed to be a plesiosaur beside the Struthiomimus? The shape of its body looks very strange to me (but I’m no expert on them).
Yes it is and I wouldn’t know either. Looked OK to me when I saw it, though I hardly looked closely!