Australia: The Land Where Time Began

A biography of the Australian continent 

Troodontidae Smartest of the non-avian dinosaurs?

Troodontids are not presently considered by most palaeontologists to be the most likely source of the ancestor of birds, the Dromaeosauridae it believed to be the most likely family of the bird ancestor. Troodontids were about the size of small adult humans. They were built for speed, with long, slender legs, they had large, hands that were flexible enough for precise movements, long skulls and serrated, recurved teeth. They had a large claw on the second toe that was similar to that of Dromaeosaurs, but smaller. It has been speculated that they may not have used this enlarged claw in hunting as probably occurred in Dromaeosaurs.

The most distinctive feature of the Troodontids was their skulls. Relative to body size, it was the largest brain case of any non-avian dinosaur, the orbits were very large, and the internal shape of the brain case indicates that the brain areas associated with sight and hearing were highly developed. It has been speculated that because of this highly developed brain they may have been the most intelligent of the dinosaurs, bus as it can't be tested it remains as speculation only. The combination of their cursorial adaptations and the highly developed brain they are believed to have been fast and agile, and to have had acute senses. They all vanished by the end of the Cretaceous.

•    Jinfengopteryx elegens  Late Jurassic-Early Cretaceous
•     Sinovenator changae Early Cretaceous
•     Byronosaurus jaffei Late Cretaceous
•     Mei long Early Cretaceous
•     Sinusonasus magnodens Late Cretaceous
•     Sauroornithoides mongoliensis Late Cretaceous
•     Sinornithoides youngi Early Cretaceous
•     Troodon formosus Late Cretaceous

Sources & Further reading

Long, John A, 1998, Dinosaurs of Australia and New Zealand, University of New South Wales Press.

Links

• Troodontidae
• DinoData