Troodon formosus was a relatively small, bird-like dinosaur from the late Cretaceous Period (68–65 MYA). Discovered in 1855, it was among the first dinosaurs found in North America, and is believed to have been one of the most intelligent.

Characteristics

This small dinosaur was around 2 m (6.5 ft) in length, 1 m (3 ft) tall, and weighed 60 kg (130 lb). It's eyes were large (suggesting nocturnal activity) and slightly forward facing, giving Troodon some depth perception.

Troodon (pronounced "Tro-odon") is Greek for "wounding tooth", and refers to the dinosaur's sharp teeth with serrated edges. Its diet consisted of smaller animals, including mammals and perhaps a significant amount of plant material as well.

Troodon' long arms that folded back like a birds', and its hands possessed partially opposable thumbs. It had large, sickle-shaped claws on its second toes which were raised off the ground when running. This claw is common in the superfamily Maniraptora, to which Troodon belongs.

Troodon has one of the largest known brains of any dinosaur relative to its body mass (comparable to modern birds). Eggs have also been discovered, in nests.

Classification

Troodon was first named Troödon (with a diaeresis) by Joseph Leidy in 1856, which was officially emended to its current status by Sauvage in 1876 — though both versions persist in common usage.

Troodon is known only from fossil teeth, which have since been conflated with postcranial material from specimens known as Stenonychosaurus. However, it has been disputed that the two species are one and the same.

A more detailed classification scheme:

• Suborder Theropoda
  • Infraorder Avetheropoda
    • Parvorder Coelurosauria
      • Superfamily Maniraptora
        • Family Troodontidae
          • Genus Troodon

References

• Prehistoric Montana
• American Museum of Natural History
• Enchanted Learning: Troodon