Protohadros was considered the oldest-known duckbill dinosaur (hadrosaur) when it was first discovered in Texas in 1984.

However, as hadrosaurs are believed to have evolved in Asia - it has since been reclassified as a member of the related iguanodon family.

Dino Facts

  • Pronounced: proe-toe-had-ross
  • Means: Early duck-billed lizard
  • Length: 19 ft (6 m)
  • Size: North America (Texas)
  • When: Mid-Cretaceous
  • Diet: Herbivorous