Dinosaurs became extinct 66m years ago, but they are still news. The media shower was created by the discovery of the perfectly preserved leg of a dinosaur in North Dakota.
It is thought that this dinosaur, discovered at the Tanis fossil site, died on the day of the mass extinction of the dinosaurs. It sounds too good to be true, but should make for a fascinating TV documentary next week, Dinosaurs: The Final days, presented by Sir David Attenborough.
We have learned a lot more about dinosaurs in the past 20 years than we did in the previous 200 years, and that's because there are more palaeontologists working on dinosaurs today than at any point in history. The discovery of important fossils has confirmed many of the once controversial and speculative ideas. Dinosaurs were warm, active animals, some were intelligent and lived in groups, and they gave rise to birds, which are now living dinosaurs.
These ideas have been a part of research for decades and have been mainstream from the 1990s onwards, but they act as a starting point for what has come since. Dozens of species of dinosaurs are represented by fossils that are preserved with fossilised feathers. We can track the evolution of feathers and their change from simple filaments to flight- capable aerofoils.
Micro structures called melanosomes, which give feathers and skin their colors, have also been discovered. That change in our ability to produce information from the fossil record opens up enormous future possibilities for research.
Reconstructing the colour of a single individual is only limited scientific value. We might be able to tell that it had a pattern that would work as camouflage, for example, or that it had very bright patterns that were likely for display, but we can't tell the whole story.
Birds moult their feathers so bright breeding colors can only be seen for a part of the year, while white winter coats can be seen in others. There could be regional variations or things might evolve and change over time. Scientists can now assess all of these possibilities, which are reasonable. There is a huge future potential for a huge expansion of our understanding of dinosaur colors and signals.
This can be used with other finds. A paper was published in 2016 that described how large, predatory dinosaurs made strange pairs of scrapes that were dug into the ground. They looked like an animal pawed at the ground and excavated a hole with each foot, and there were lots of pairs. They didn't look like any known nest and wouldn't work well, and there was no indication that they were digging for food or water. What they do look like are the marks left on the ground by different groups of modern seabirds. This was proof of dinosaur displays and courting.
It's a fascinating find and some great deductive work went into eliminating the possible explanations to leave this as the most likely one. It provides information about how a dinosaur tried to find a mate, but it leaves a lot of unanswered questions. It's not easy to tell dinosaurs apart from their tracks.
It would be great to say that it was a tyrannosaur, but we don't actually know, and it's hard to find out. We don't know what else they might have been doing. There would have been a lot of other rituals going on, like calls between couples, all kinds of possible dances or other moves, and feathers could have been fluffed up and shaken. Was this going on for a while? It's almost impossible to imagine how we could know.
There are two distinct gaps in our knowledge of dinosaurs, the ones we are likely to fill and the ones that are almost impossible. It doesn't mean they are out of reach. Until a few years ago, I would have said that dinosaur colors were not only not known, but something we could never know, and that was true right up to the point. When researchers realized that melanosome shape was linked to colour and that melanosomes could be preserved, it opened up a whole new set of possibilities. The more conventional gaps will still be filled in. To be able to piece together the evolutionary history of these most incredible reptiles, fossils of new species, from new areas, and new data are being found.
We have more than enough pieces to see what the true picture is, and more and more gaps are being filled, so for all the frustrating missing pieces that we have in the puzzle of dinosaur biology, we have more than enough pieces to see what the true picture is. The future of dinosaurs is a most rosy one because there are plenty that we will probably never find, but it won't stop our knowledge from growing or our understanding improving.
Dr Dave Hone is a senior lecturer at Queen Mary University of London. He presents a Terrible Lizards show. The Future of Dinosaurs is his newest book.
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