Are dinosaurs extinct? theropod dinosaurs are the bipedal ("two-footed") carnivores of tyrannosaurus rex fame that many people imagine when they think of dinosaurs-sharp teeth, claws, long tails, and a taste for flesh. did these dinosaurs go extinct?

Yes and no.

Explanation:

All non avian dinosaurs went extinct. But a small branch of the dinosaurs still survived (avian dinosaur or birds).

The correct answer is - Yes, they went extinct;

All of the dinosaurs, bipedal or four-legged, went extinct around 66 million years ago. Even though they were the dominant living organisms and ruled the planet, they were still not able to sustain the damage done by the asteroid collision with the Earth. The asteroid that collided with the Earth around 66 million years ago created such a strong explosion, that from the impact itself it managed to kill pretty much everything in the surrounding area. Also, there were hot waves of air travelling in high speeds across the globe that fried any animal and plant that were not sheltered. Because of the released force of the asteroid, the volcanoes activated around the globe, and together with the enormous amount of dust from the asteroid collision that went in the atmosphere, the volcanoes too released a lot of ashes, thus creating a cloud around the globe, stopping the Sun light for some time. This all resulted in mass dying out of the dinosaurs in a very short period of time. Their closest relatives that managed to survive and we can see in the present are the birds.