The rhino three times bigger than an elephant

Is a mouse more powerful than a dinosaur? The fearsome T rex gets all the attention. But a scientist says the first mammals were just as amazing. What's happening?  When dinosaurs roamed the Earth, they were not alone. There were mammals too. There was the maiopatagium which could swoop through the air. There was the repenomamus which ate dinosaurs.  But lots of them have been forgotten. Now, a new book celebrates the oldest mammals.  Find out more Mammals first appeared 325 million years ago. They lived in swamps and they were small. But over time they grew into giants.  There were armadillos as big as cars. There was a rhino called paraceratherium that is the biggest land mammal of all time.  The ancient mammals were like they are today. They had fur. They fed their young with milk. A new book wants to celebrate them. The writer says they are just as important as dinosaurs.  But others disagree. Dinosaurs ruled the Earth for 100 million years. They only died because of an asteroid from space. If it had not hit our planet, they would still be in charge today.  Is a mouse more powerful than a dinosaur? Some say Yes: Big teeth aren't everything. A fast mouse can outsmart a giant lizard. Mammals were around before, during and after the dinosaurs. We are history's great survivors.  Others think  No: There is a reason dinosaurs ruled for so long. And the more we learn about them, the more spectacular they become. Or... This isn't a competition. All animals adapt to their environment and are spectacular in their own way. And as mammals ourselves, it is impossible to be objective. KeywordsAsteroid - A small body in space, made of metal and rock material. Asteroids usually orbit the sun, but if knocked off course they can be drawn into Earth’s gravity and fall towards it.