TheropodaTroodontidae

Troodon formosus

Troodon formosus skeletal reconstruction, left lateral view, reconstructed length ~2.4 m.
Scale bar = 50 centimeters
Taxon
Troodon formosus Leidy, 1856
Reconstructed length
~2.4 m (8 feet)
View
Left lateral
Drawing
© Scott Hartman
Drawn
2010, revised 2026
Clade
  1. Theropoda
  2. Tetanurae
  3. Coelurosauria
  4. Maniraptoriformes
  5. Maniraptora
  6. Paraves
  7. Troodontidae

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Troodon is the archetypical troodontid, living during the Late Cretaceous of North America. As in other troodontids, it was a lightly-built, long-legged omnivore noted for their large brains relative to body size. Troodon had serrated, semi-leaf-shaped teeth and large forward-facing eyes suited to keen vision.

Not everyone agrees that Troodon is a valid genus, however. The original material is considered undiagnostic by some researchers, and in the century+ since it was named other troodontid species were lumped in that don’t belong. Some would prefer that Troodon be dropped and the remains put into other genera, including Stenonychosaurus. Others prefer preserving the name Troodon - this is another case where we will have to watch how the debate plays out in the scientific literature in the years to come.