Dinosaurs: Mesozoic Era, Anatomy, Extinction, and Evolution

What is the approximate time range of the Jurassic Period?

200-146 million years ago.

Which era includes the Jurassic Period?

The Mesozoic Era.

What is the nickname for the Jurassic Period?

The Age of the Dinosaurs.

What was the Triassic-Jurassic Extinction event also known as?

The CAMP (Central Atlantic Magmatic Province) extinction event.

Approximately what percentage of species went extinct during the Triassic-Jurassic extinction?

50% of all species.

How did the Triassic-Jurassic extinction facilitate the rise of dinosaurs?

It caused other archosaurs to vacate terrestrial ecological niches, allowing dinosaurs to assume dominant roles.

What is a 'disaster taxon'?

A species that benefits from an extinction event by filling vacant ecological niches.

What is the literal etymological meaning of the word 'dinosaur'?

Terrible lizard.

Are dinosaurs biologically classified as lizards?

No, this is a common misconception; they evolved from a branch of archosaurs (diapsid reptiles).

What evidence suggests that dinosaurs were warm-blooded?

Growth rates and the discovery of fossils in arctic regions.

What is the acetabulum in dinosaur anatomy?

A hole in the hip structure where the femur (thigh bone) articulates.

Which three bones form the dinosaur pelvis?

The ilium, ischium, and pubis.

What is a key distinguishing feature of dinosaur skeletal stance compared to other reptiles?

Their hind limbs are positioned directly beneath the body, rather than having a sprawling leg posture.

What is the primary evolutionary benefit of the erect posture found in dinosaurs?

It likely improved locomotion and energy efficiency.

What anatomical feature is commonly found on the feet of many dinosaurs?

Three-toed feet.

How long did dinosaurs dominate the Earth in total?

Approximately 165 million years.

Do all tetrapods share the same basic hip bone structure?

Yes, all tetrapods share the ilium, ischium, and pubis structure.

How does the dinosaur pelvis differ from that of other reptiles?

Dinosaurs have a hole in the center of the pelvis (the acetabulum), which is a feature similar to mammals.