Some of the early, primitive dinosaurs also went extinct, but other more adaptive dinosaurs survived to evolve in the Jurassic.

These footprints were likely made by an unidentified, primitive dinosaur similar to Coelophysis.

Fabrosauridae is a proposed family of primitive ornithischian dinosaurs from late Triassic and Jurassic.

The most primitive dinosaurs with evidence of a vocalizing syrinx are the enantironithine birds.

They gave us this form because it would ensure our survival amid the more primitive dinosaurs of eons past.

This small, primitive dinosaur is actually more interesting to science in many ways than its larger, more famous relatives because it teaches us more about evolution.

Most modern scientists find that Avimimus in fact belongs to a diverse group of bird-like dinosaurs more primitive than Archaeopteryx, the oviraptorosaurs.

This led some scientists to think that segnosaurs were a late-surviving suborder of primitive dinosaurs.

Hesperosuchus was a contemporary of Coelophysis, a primitive predatory theropod dinosaur.

Concavenator was a medium-sized (roughly 6 meters (20 feet) long) primitive carcharodontosaurian dinosaur possessing several unique features.