Speculation vs. science
Much of palaeobiology used to be speculative – how much did that dinosaur weigh, what colour was it, did it care for its young, how fast did it run? How could we ever answer those questions unless we had a time machine to go back to the Age of the Dinosaurs? In the past 30 years, astonishing new fossil discoveries and a host of smart new computational techniques mean we can actually answer those questions. What have we learned?
The ‘top ten’ dino facts
- Some dinosaurs had feathers that carried patterns of colourful stripes and blobs.
- Tyrannosaurus rex had a bite force that was ten times more powerful than that of the biggest biter today, the Great white shark.
- Equally though, T. rex could not gallop or run, but ambled along at a leisurely pace.
- Dinosaur babies all hatched from eggs, and they were tiny – a 1 kg baby vs. a 50-tonne mother.
- The sauropods such as Diplodocus or Brontosaurus got to be so huge (50 tonnes) compared to an elephant (5 tonnes) because they had a combination of low-input warm-bloodedness (so they didn’t have to eat a huge amount), tiny babies and egg-laying, and minimal or no parental care.
- Dinosaurs dominated the Earth for 165 million years, but they rose to dominance only after some major changes in climate.
- Dinosaurs had a super-efficient respiration system like a bird, drawing the air into their lungs, then passing it through air sacs around the backbone, and back out through the mouth; this is a much better way to exchange oxygen and carbon dioxide than the tidal system in mammals.
- The giant plant-eating sauropods divided niches by feeding in different ways – some pulled back on tree branches, stripping the leaves off as they did so, whereas others crunched leaves and branches whole.
- So far, nobody has found any dinosaur DNA, and indeed this is unlikely as DNA is a very fragile molecule that breaks up in 100 years or less.
- Dinosaurs may have been in decline – just a little – for the last 40 million years of the Cretaceous, as climates got colder, but they were then done for by the meteorite strike 66 million years ago.